Accusations of blame by campaigner Alan Bates after a subpostmaster deliberately stepped in front of an oncoming bus were “unhelpful”, former Post Office boss Paula Vennells said.

Martin Griffiths walked in front of the bus on September 23 2013, after he had been deemed culpable for an armed robbery at his Hope Farm Post Office branch in Cheshire in May 2013.

He had also previously written to the Post Office in July 2013 about a £39,000 shortfall at his branch between February 2012 and May 2013.

He was sacked in July of the same year.

An email from Mr Bates criticising the Post Office after Mr Griffiths had stepped in front of the bus was shown during Ms Vennells’s evidence to the Horizon IT inquiry, to which Ms Vennells said the campaigner was “rightly very, very angry about this”, but his language about her colleagues “was extreme”.

In the email, Mr Bates said Mr Griffiths’s case was a “prime example of the thuggery being exerted on defenceless subpostmasters” as he was said to have been denied legal representation during a meeting by “arrogant and uncontrolled Post Office personnel”.

Jason Beer KC asked: “You say in your statement that ‘this was a time of great distress for Mr Griffiths’s family, and I felt the accusations of blame were unhelpful’… is that right that you felt that Mr Bates’s accusations of blame were unhelpful?”

Ms Vennells responded: “I think at this stage some of those accusations of blame were unhelpful, yes, because the Post Office needed to respond to this properly and at that stage, I had no understanding as to what had gone on.”

Ms Vennells also broke down in tears as she discussed Mr Griffiths and a previous experience of a Post Office colleague taking their own life.

The inquiry was shown an email from Mr Bates to Ms Vennells and others in which Mr Bates said he had received an email from a relative of Mr Griffiths the day he walked in front of a bus and was in hospital, and the relative said “the Post Office had driven him to suicide”.

Mr Griffiths died in hospital three weeks later.

An email chain between former Post Office general counsel Susan Crichton and Ms Vennells was also shown, in which Ms Vennells says “if it is an attempted suicide, as we sadly know, there are usually several contributory factors”.

Asked why she was raising the fact that there were usually several contributory factors, she said she was “very sorry”, adding: “Every email you will see from me about Mr Griffiths, I start with him and how he was and how his family are. The Post Office took far too long to deal with it.”

She added that as chief executive, she had to communicate “something so serious as this to the board” and was trying to find out “whether there was anything else behind it”, then broke down in tears as she mentioned a previous experience of a Post Office colleague taking their own life and spoke to their family who explained that there were “other issues involved”.

Speaking of Mr Griffiths’s case, she said: “I imagine that what I was doing here in this email was recalling that previous incident, but what you will see is that in every email I wrote on this, my first concern was for Mr Griffiths and his family, and as I said in my statement, sorry is an inadequate word, I’m just so sorry that Mr Griffiths isn’t here today.”