Sir Patrick explains no single person is responsible for the failure of the scheme:

"Responsibility for what went wrong lay not just with one individual or group but with a broad range of persons and organisations involved across a variety of areas relating to the design, approval, management and administration off the scheme throughout its life."

He says there was "a multiplicity of errors and omissions" and repeated missed opportunities to correct the flaws in the scheme.

"DETI should not have ended up in the position where an urgent suspension of the scheme was required and could only be affected by means of further legislation," says Sir Patrick.

"While reasonably effective in outcome, it was not well managed," he adds.

"Corrupt or malicious activity on the part of officials, ministers, or special advisers was not the cause of what went wrong with the NI scheme, albeit the inquiry has identified some instances where behaviour was unacceptable."

He put the downfall down to an "accumulation and compounding of errors and failures over time" as an issue "on the part of all those involved in differing roles".

While they have been identified, he says there is "no guarantee the weaknesses shown in governance, staffing and leadership revealed by inquiry could not combine again" in the future.

Sir Patrick says the nature of the relation between DETI as owner of the RHI scheme and Ofgem as the chosen scheme administrators was unsatisfactory.

The service Ofgem provided to DETI fell below the standard that DETI could reasonably have expected.

It did not share important docs with DETI.

One example was a fraud prevention strategy – the document contained a substantive and fundamental error, indicating that the NI scheme had the protection of tiering of some tariffs, which it did not

More on Spads, and Sir Patrick says there was "no effective system in force for special advisers register their interest on a sufficiently regular basis" or "requirement or instruction to register potential conflict of interest in writing".

He goes on to outline a number of "instances of unacceptable behaviour by special advisers" relating to information sharing of confidential documents.

UUP chief whip Robbie Butler says: "The need to robustly investigate the findings cannot be underestimated.

"The legitimate users suffering in a physical or mental health sense could be the biggest losers in this debacle.

"We need to show maturity and be brave in the steps to ensure the failure in these documents does not happen again.

"There was an unhealthy culture in the availing of treasury money."

Sir Patrick says that during 2015 too much information about proposed changes to the scheme was shared by DETI officials with third parties "often before the proposed changes had been sanctioned by the minister".

There was no adequate or effective training for officials on how to handle relations with external commercial organisations, he adds.

Sir Patrick says the NI ministerial code did not include "significant and helpful provisions" relating to the appointment of special advisers.

"There was a repeated failure to comply with the intent with the provisions of the Civil Service Special Advisers Act, 2013," he say.

SDLP leader Colum Eastwood says the RHI Inquiry report presents an urgent case for reform of the processes of government in Northern Ireland.

He says the report must drive immediate change.

Mr Eastwood adds that the Northern Ireland Civil Service is also in need of immediate reform to ensure that staffing levels are appropriate, that sufficient expertise is available, that advice to ministers is fulsome and that detailed minutes of engagement with ministers are prepared.

In relation to the DETI staff, Sir Patrick says there was a "culture of delivery".

He says "although objectionable in principle," such a culture meant "that issues that should have been escalated were not and too often matters were presented in an unduly positive light".

He goes on to outline that when amendments were introduced to the scheme in 2015 the market "quickly adapted" which resulted in "virtually no difference before and after the changes".

Image source, Pacemaker

"The Democratic Unionist Party accepts the report and thanks the inquiry for their meticulous work.

"The party co-operated fully with the Inquiry and employed external independent consultants to ensure complete fulfilment of the Inquiry’s requests.

"The party leader has apologised personally and corporately for mistakes made because we should have done better.

"We will and must do better in the future. We will take time as an organisation to study the report and learn lessons from its findings.

"The report details the failures and missed opportunities of all involved in the scheme.

"Significantly, the Inquiry has concluded that:

“corrupt or malicious activity on the part of officials, ministers, or special advisers was not the cause of what went wrong with the NI RHI Scheme. . . . Rather the vast majority of what went wrong was due to an accumulation and compounding of errors and omissions over time and a failure of attention, on the part of all those involved in their differing roles, to identify the existence, significance or implications of those errors and omissions.”

You can read the full Arlene Foster statement here., external

The chairperson says that in 2012 the DETI minister, who had already been told incorrectly by officials that the NI scheme was projected to provide the highest renewable heat output for the best value, was presented by officials with a draft regulatory impact assessment to sign, which although it enumerated a number of risks presented by the scheme did not include all the necessary costs information in respect to scheme.

"While the minister should not have been presented with a document which lacked all the necessary costs information she equally should not have signed it in those circumstances," he says

"Many of design flaws in the scheme were quickly identified outside DETI by other parts of public sector and private sector," says Sir Patrick.

"Bodies such as Invest NI and Action Renewables, in light of what they appreciated about the scheme from an early stage, could and should have done more to make DETI aware of potential exploitation of the scheme and to query with DETI whether the scheme as operating as it was intended," he adds.

Finance Minister Conor Murphy, of Sinn Féin, is now addressing the media in the Great Hall.

His department called the inquiry, although he was not the minister at the time.

He says: "It’s over to us to turn the recommendations into real action and reform.

"We need an effective government and good practice and handling of our finances.

"An issue such as this can never arise again.

"An action plan to implement them will be brought forward."

More from First Minister Arlene Foster, who says: "Whilst I, my party and others have much to reflect upon, I am pleased that there has been no finding to support those who alleged improper motivation or indeed in some cases that I, or the party, was motivated by some financial considerations in the actions or omissions that took place.

"Amongst the legitimate criticisms, some chose to use the crisis to deliberately mislead.

"This report will require careful consideration so that collectively we can ensure there is no repeat of the many systemic failings across government."

Sir Patrick says DETI's "internal governance systems were ineffective where the NI scheme was concerned".

"The system of operational planning, internal control risk management and internal audit, together and over time, failed to uncover important issues or to act as an appropriate conduit to deliver important information to managers about flaws and mounting risk to NI RHI scheme."

He adds that a failure due to "a combination of inadequate corporate responses to learning from past mistakes, weak governance systems and officials not adhering sufficiently or adequately to multiple reporting systems which did exist".

Arlene Foster has welcomed the publication of the RHI report and says "for my part I am determined to learn from my mistakes".

She adds: "In my conference speech to the Democratic Unionist Party in 2018 I indicated that the best of intentions do not make us immune from mistakes and misjudgments.

"Today I again apologise for my failings in the implementation of the Renewable Heat Incentive scheme."

Sir Patrick says the NI Civil Service policy of deploying "generalist civil servants without having due regard to the requirements of certain roles particularly in business area such as the energy division was a contributory factor to the problems within the Northern Ireland scheme".

He says the absence of relevant and appropriate tailored project management throughout the lifetime of the scheme "also had long-term consequences"

Sir Patrick outlines that there were instances where documents and advice for ministers were "inaccurate, incomplete and misleading".

He says mistakes were then repeated in "subsequent documents" and not identified by recipients of those documents and that the "crucial safety features" the most significant of which was "any form of budget control mechanism" were not introduced to the Northern Ireland scheme.

Sir Patrick adds that this was in spite of a desire by DETI "for consistency of approach with GB" - which had controls in place.