Former enterprise minister Jonathan Bell told the inquiry last month that he had "great concern" that he wasn't kept informed about the surge in applications to the RHI scheme as it developed in autumn 2015.

Inquiry counsel David Scoffield says the minister doesn't seem to have been updated on developments with the scheme at any stage between late-August and mid-November that year.

Image source, RHI Inquiry

Dr Andrew McCormick says he personally had some awareness of the surge up to and including early November, when he had very clear information.

"We probably could have and should have put more detail to him in that period," he concedes.

In his witness statement, Dr Andrew McCormick says a massive spike in applications to the RHI scheme in the weeks before the cost controls came into effect in November 2015 "was not foreseen".

Asked if he stands over that view, he accepts that he was aware there'd be a spike to some extent but not as big as the one that occurred.

The key issue that led to the spike was the length of time between a decision being taken to add cost controls and actually putting them into force, he says.

The department publicly announced the changes to the scheme on 8 September 2015, a full 10 weeks before they came into effect.

That wasn't helpful, says Dr McCormick, but he adds that given that knowledge of the changes had spread through industry long before that it probably didn't make a great deal of difference.

Officials at DETI had been briefing those in the renewable energy and agri-food sectors about the impending changes for months before that.

Dr Andrew McCormick is asked about the source of the reluctance to expedite changes to the RHI scheme in the summer and autumn of 2015.

In his written statement, he says officials suspected DUP adviser Dr Andrew Crawford was the prime mover.

Image source, Getty Images

That was due to his familiarity with the scheme from his time as adviser to Arlene Foster when she was the DETI minster during its first few years of operation and because he "strong connections to the farming community".

However, Dr McCormick says there was no suspicion of any conflict of interest on Dr Crawford's part.

Between them, Dr Crawford's brother and two of his cousins have 11 biomass boilers registered on the scheme.

Civil servants at DETI were not part of any attempt to shift blame for the RHI scandal on to Jonathan Bell, insists Dr Andrew McCormick.

In February 2016, when the scramble was on to get the scheme shut down, the then head of the Northern Ireland Civil Service Sir Malcolm McKibbin wanted to know more about what had gone on the previous summer.

Dr McCormick told him that DETI's actions in relation to the scheme had been "informed by a clear ministerial steer".

Image source, Pacemaker

But he's challenged on that, given that he knew that direction was coming from Mr Bell's adviser, not the minister himself, and that there had been a serious fallout between the two men.

Sir Patrick Coghlin says that Dr McCormick "knew perfectly well" that Mr Bell "didn't have a steer at all".

The witness accepts that if he was writing the statement to Sir Malcolm today "it would be different".

"Well I would hope so," bites the inquiry chair.

There was only "very slight" resistance from civil servants to a push from a DUP adviser to delay the RHI scheme's cost controls by a month, admits Dr Andrew McCormick.

He told the inquiry yesterday that the postponement from October to November 2015 came after "pressure" from Tim Cairns (below), an aide to the then DETI minister Jonathan Bell, at a meeting that August.

Image source, RHI Inquiry

According to Mr Cairns, he only asked a "softball questions" about whether October was the latest date that officials would allow.

Mr Bell "wasn't very active in the discussion", he says, and there was "no resisting" from the minister to what his adviser had put forward.

Stormont parties would sometimes not want the reasons behind their decision to have been disclosed to the public and therefore they weren't recorded to prevent a leak, says Dr Andrew McCormick.

Dame Una O'Brien, the inquiry panellist with vast experience as a senior Whitehall civil servant, says that has "very wide ramifications".

Image source, RHI Inquiry

Not taking notes means that key issues are "never even recorded for the people who have to implement the decision" and officials are left to "make it up or try to work out what that reason was".

The makes it difficult to get things done in a "cost effective and organised way" - that's a point with which Dr McCormick agrees.

Sir Patrick Coghlin isn't happy with Dr Andrew McCormick's suggestion that Stormont ministers were "tweeting from the executive table".

"Am I right in think that's somebody using social media to pass on information about an active debate that;s taking place?" asks the inquiry chair, curious as to whether there was a code of practice in place to prevent that.

Dr McCormick says "there are rules" but enforcing them is "politically very difficult".

Image source, RHI Inquiry

Sir Patrick says it would "come as something of a shock" to not only him but the vast majority of the Northern Ireland population that the rules were being "completely ignored" by political parties.

"There cannot be, from a public point of view, a positive perception of the political process if that occurs."

The witness says that given that devolution at Stormont had only been running for 10 years since 2007 politicians had a "need to work out a mature way of working" - he claims that a decade is "quite a short time" in which to do that.

There was a concern among Stormont officials that "if you write something down it'll probably appear in the newspapers", says Dr Andrew McCormick.

In his written statement, he says that the "reality is that almost any document, however private, could be leaked".

Image source, RHI Inquiry

Elaborating on that, he tells the inquiry that it's a particular problem in the devolved administration because the "tensions are multidimensional in the nature of enforced coalition".

He adds that the parties other than the DUP and Sinn Féin always felt they were getting "second-class access" to information.

The senior official describes a culture where "tweeting from the executive room" was common "when in theory [it] is a space for private, confidential government business to be done".

Officials were "in a culture of very limited record keeping", admits Dr Andrew McCormick, who accepts "personal responsibility" as the top civil servant at DETI at the time.

His confession comes as the inquiry hears that there are no minutes of a key meeting at which it was agreed to delay the RHI scheme's cost controls - that was a huge decision that had big implications for the budget.

The delay in bringing the cost controls into effect meant more applicants were to sign up to the scheme when it was at its most lucrative.

Image source, Getty Images

"We should not have got into this culture of very limited record keeping - it's not a good thing," he says.

It wasn't just happening in his department, though, he adds - it had "become a pattern... in other places" in the civil service as well.

His view matches that of David Sterling, the head of the Northern Ireland Civil Service, who told the inquiry in March that meetings were not minuted in order to frustrate Freedom of Information requests.

One of the key civil service figures in the RHI debacle, Dr Andrew McCormick was the permanent secretary - the top civil servant - at the Department for the Economy, formerly DETI, which set up the energy initiative.

He was in that post at the time when big cracks began to appear in the RHI scheme through until after its emergency closure.

He had to clear up much of the mess that was created in the department by the political fallout over the scheme in late-2016 and early-2017.

He has since switched roles and now has just as big a task on his hands as he deals with all things Brexit as Stormont's director general of international relations.

His witness statement to the inquiry makes for a dramatic read and you can find it in three parts - here, external, here, external and here, external.

He appeared before the inquiry twice last month, saying that he didn't "recall any resistance" from DUP advisers to the RHI scheme being placed on the agenda during ministerial meetings.

Quick fact - his PhD was in isotope geochemistry.

Returning to the witness chair for the fourth time, Dr Andrew McCormick has the jacket off, ready for an all-day session in the spotlight.

Image source, RHI Inquiry

The inquiry's senior counsel David Scoffield QC will be asking the questions.

He dives straight back in to where he left off yesterday, discussing a meeting at which civil servants, the enterprise minister and his adviser agreed to delay the RHI scheme's cost controls by a month.

Jayne McCormack
BBC News NI politics reporter

Two DUP advisers withheld key information from officials about abuse of the RHI scheme, said a senior civil servant.

Image source, Pacemaker

Arlene Foster's aide Andrew Crawford sent an email to his adviser colleague Tim Cairns in July 2015, mentioning how poultry farmers were "heating empty sheds" because the subsidies were so lucrative.

Dr Andrew McCormick told the inquiry that had the threat to the scheme's budget been communicated clearly to departmental officials it would have been acted on.

BBC News NI

An independent inquiry into the RHI scandal was established in January last year by the then finance minister Máirtín Ó Muilleoir.

He ordered it in the wake of the huge public concern and what was then a major political crisis surrounding the scheme.

The RHI Inquiry began in November last year and Sir Patrick Coghlin (below), a retired Court of Appeal judge, is its chair and has been given full control over how it will operate.

Image source, Pacemaker

It is looking at:

• the design and introduction of the RHI scheme
• the scheme's initial operation, administration, promotion and supervision
• the introduction of revised subsidies and a usage cap for new scheme claimants in autumn 2015
• the scheme's closure in February 2016

For more information on the RHI Inquiry, you can read our handy Q&A.

When the scale of the overspend emerged, public and political concern rocketed.

As the minister in charge of the Stormont department that set up the RHI scheme, the DUP leader Arlene Foster faced calls to resign from her role as Northern Ireland's first minister in December 2016.

Image source, PA

She resisted, and Sinn Féin's Martin McGuinness then quit as deputy first minister in protest at the DUP's handling of what had by then become a full-blown political crisis.

That move brought about the collapse of the Northern Ireland Executive. Now, well beyond a year-and-a-half on from that, Northern Ireland remains without a devolved administration.

You can find much more detail on the RHI scheme in our need-to-know guide.

The budget of the RHI scheme ran out of control because of critical flaws in the way the initiative was set up.

Claimants could effectively earn more money the more fuel they burned because the subsidies on offer for renewable fuels were far greater than the cost of the fuels themselves.

At one point the estimate for the overspend was set at £700m if permanent cost controls weren't introduced - temporary cuts have since pulled the budget back on track for now.

Whatever the scale of the bill, it will have to be picked up by the Northern Ireland taxpayer.

The Renewable Heat Incentive scheme - or RHI for short - came to the fore of the Northern Ireland public's knowledge in late 2016.

The fallout from the scandal attached to it is still being felt in the region's politics today.

Image source, Getty Images

The scheme was set up by the Northern Ireland Executive in 2012 as a way of encouraging businesses to switch from using fossil fuels to renewable sources for generating their heat.

Those who signed up were offered financial incentives to buy new heating systems and the fuel to run them.

The Stormont Estate's a riot of autumn colour this morning - it's hard to resist the temptation to spend the morning kicking through the drifts of leaves but resist we must.

Welcome to day 103 of our coverage of the Renewable Heat Incentive Inquiry - government official Dr Andrew McCormick faces another day in the witness spotlight.

The session kicks off in a few minutes so stay with us to watch a live stream and follow our text reporting throughout the day.