Alan Cook says he'd never come across a situation before where a "trading entity could initiate prosecutions itself".

He repeats that he had no idea the Post Office was the sole arbiter over whether or not its employees were taken to court.

Asked why he wasn't made aware of this part of the business, he says others may have "assumed I knew that".

He repeats his regret for not doing more to learn about these court cases that were going on during his time at the top.

Hundreds of people were prosecuted while Cook was managing director between 2003 and 2010.

The inquiry is now looking at Cook's witness statement, in which Cook claims that he did not have any oversight over the prosecutions and was not aware that they were taking place.

He says there were expressions used like "this is going to court", so he assumed that the police had been involved - an assumption he says that he was sad to make.

"I had too much assumed knowledge," he admits.

Image source, Post Office inquiry

Cook is being taken to task over how much he knew about the Post Office taking sub-postmasters to court.

Remember, the Post Office had the unusual ability to take its own branch managers to court if they suspected them of theft or fraud, and we know that led to lots of wrongful convictions.

Cook tells the inquiry he was aware there were court cases going on but that it wasn't until more than three years into his job that he realised the Post Office could take the decision to prosecute someone without any review or approval from another body.

He said the evidence in some of the cases against sub-postmasters "was quite compelling, but that's not really the point - it's about how much independence there was in the process".

Cook also says there would have been a "higher bar" for prosecutions if the decision was left up to another authority - but repeats he simply didn't know until years into the job that the Post Office was taking these decisions for itself in "about two thirds of cases".

Image source, Post Office Inquiry

Former Post Office director Alan Cook is now discussing more about the legal structure of the Post Office.

Inquiry lawyer Stevens puts to Cook whether he thinks the Post Office would have benefited from its own legal team, instead of being centralised within the Royal Mail umbrella group.

"I would've liked its own legal team, I would've felt happier, I would have felt more accountable," he says, before adding that he doesn't believe this would have necessarily helped in unearthing the problems "much quicker" as a result. But I would have been closer to the issue, he says.

The Post Office did not have its own legal team, he says, because it was not the proposed organisational structure at the time that he was appointed to his role as managing director. "It was a non-negotiable when I was being appointed."

Cook says he was a little reluctant when he was being offered the job because he would have preferred to have his "arms around everything".

He says when he was offered the role he was uncertain about the fact his predecessor was titled as chief executive where he was offered the job of managing director.

He says he wasn't sure if he would have the same level of accountability, and his reluctance wasn't a question of ego over the job title.

Cook is now being pressed on how the internal Post Office structures designed to provide accountability were arranged during his time there.

He says the Post Office's board was responsible for overseeing its business and agrees it had an important role in identifying risks it could face.

Stevens, the inquiry's lawyer, asks a series of technical questions about the set-up of the Post Office, which at that time came under the broader Royal Mail umbrella.

He says the two shared a number of departments - including, importantly, legal and IT - which didn't report directly to him when he was on the Post Office board.

Still talking about his career background, Stevens continues to ask Cook about his time as managing director at the Post Office, which he was appointed to in March 2006.

Cook continues to outline his history as a businessman, explaining how his role as managing director at the Post Office was his first time as non-executive director. He concedes that, until then, he had sat on boards, but in later life he is "much more expert now than before".

Cook says that he was indeed aware of his overall responsibilities in challenging management in his role, which included to "express reservations, if [he] felt so inclined" and contribute to the overall conversation.

He adds that his expectations for standards of corporate governance in the publicly owned company were different compared to his previous roles, and notes that, in his belief: "corporate governance is better performed if the non execs are greater in number than the executives."

Sam Stevens, counsel to the inquiry, begins by asking about Alan Cook’s role as a non-executive director of the Post Office and if Cook still believes, as he says in his witness statement, that he had a duty to challenge management on any aspect of the business - to which Cook says he does.

Cook says he had “quite a bit of dealings” prior to becoming a non-executive director, but says it was a “different order of magnitude” becoming a board member, explaining how the Post Office set up a programme for him to better get to know the organisation when he started.

James Gregory
Reporting from the inquiry

A poignant moment already from Cook as he begins today by putting on record what he describes as a "personal apology" to the sub-postmasters, sub-postmistresses and their families for what they have been put through.

He says he feels it is an "important thing for me to say upfront".

James Gregory
Reporting from the inquiry

It looks like proceedings will start on time today as we've just been told the hearing is about to begin.

The room has been filling up with lawyers and members of the press.

Alan Cook, who worked as the managing director of the Post Office between 2006 to 2010, is now being sworn in and will soon begin giving evidence to the inquiry.

Stick with us as we bring you the latest.

Today's Post Office inquiry session is just about to get started.

We will hear first from Alan Cook, who was managing director of the Post Office from 2006 to 2010.

You can watch all the latest from Aldwych House by pressing Play at the top of the page.

Inquiry to hear from two men running Post Office at height of prosecutionspublished at 09:20 British Summer Time 12 April

09:20 BST 12 April

Zoe Conway
Employment correspondent, reporting from the inquiry

The inquiry will hear from two men who were at the very top of running the Post Office at the height of the prosecutions.

Alan Cook was a managing director and on the company board, while Adam Crozier was the Chief Executive of the Royal Mail Group which owned the Post Office.

Victims of the scandal have asked why Crozier hasn’t faced more scrutiny. He says he had no involvement in the Horizon issue while at Royal Mail.

It’s interesting that he’s only being questioned for an afternoon - compare that to former CEO Paula Vennells, who will be grilled for three days in May.

Does that mean the inquiry is less interested in what he has to say than campaigners had hoped?

Of course, there is no such thing as a quiet day here. Even when the evidence is at its driest, its most technical, it is quietly devastating.

James Gregory
Reporting from the inquiry

Good morning from central London. I’m at Aldwych House, where the inquiry is being held, and I’ll be in the room where two former senior executives will be giving evidence.

The usual cohort of camera crews and photographers have been stationed outside this morning awaiting the arrival of Alan Cook, managing director of the Post Office between 2006 and 2010, and Adam Crozier, who led Royal Mail when it was owned by the Post Office between 2003 and 2010.

Now chair of BT, Crozier left Royal Mail to run ITV. He did not feature in the ITV drama which laid bare the plight of the sub-postmasters andsub-postmistresses.

Up until now, we’ve heard very little from either man about their time in their respective roles and what they knew about the scandal. That’s all about to change today.

Image source, PA Media

We'll be hearing from Alan Cook first this morning. He was managing director of the Post Office from 2006 to 2010, a fairly long period which covers some of the key years when the Horizon scandal was unfolding.

Former Post Office chairman Sir Michael Hodgkinson said Cook was recruited for the role for his “substantial financial services experience and a close relationship with the government”.

He has previously told, external the Milton Keynes Citizen he would “never forgive himself” for not knowing about the wrongful prosecution of sub-postmasters, and said he was not aware of problems with Horizon until shortly before he left.

Cook has held senior positions at a number of well-known businesses, including a controversial spell running the insurance company LV= during a failed attempt to sell the company to a US firm.

He has also been involved with the Highways Agency, Department of Transport, Financial Ombudsman Service and Office of Fair Trading.

BBC News has previously revealed he was paid more than £3m during his time at the Post Office.

Aoife Walsh
Live reporter

Good morning and thanks for joining us as we take you through another day of evidence at the Post Office inquiry.

Today we’ll be hearing from two former senior executives. First is Alan Cook, who was managing director between 2006 and 2010.

Then it's Adam Crozier, who ran the Royal Mail - which used to be part of the same group as the Post Office - between 2003 and 2010.

Many of you won’t have heard of the two men - but the inquiry will hope they have crucial information on what was happening behind the scenes at the Post Office while this scandal was gathering pace.

It’s a slightly earlier start and finish today. Evidence will begin around 9:30 BST and we expect to finish sometime after 15:00.

We’ll be following all the questioning and explaining what it means throughout the day.