The chief executive of the Post Office has said previous leaders may not have been “held to account” for being aware of problems with the Horizon IT system.

Nick Read has been giving evidence at the long-running inquiry into faults with the system which sparked the wrongful prosecutions of hundreds of postmasters.

Mr Read said: “I think one of the themes that has emerged amongst colleagues still working within the organisation is that many of the leaders historically who have appeared before this inquiry appear not to have been held to account, if in indeed they were aware of and understood other issues associated with Horizon in the past.”

Post Office Horizon IT scandal
Former Post Office boss Paula Vennells has apologised to postmasters during her appearance at the Horizon IT inquiry (Post Office Horizon IT Inquiry/PA)

Former chief executive Paula Vennells is one of the senior members to have given evidence at the inquiry, during which she apologised to postmasters but denied there was a conspiracy to cover up the Horizon scandal.

The scandal saw more than 900 subpostmasters prosecuted for stealing, based on incorrect information from an IT system known as Horizon.

A long-running inquiry into the issue has been gathering evidence of the failings of the system at the Post Office, after the convictions of hundreds of postmasters were quashed earlier this year.

The Post Office continues to use the system despite heavy criticism over the issues.

Thousands of Post Office subpostmasters said they have still witnessed unexplained problems with Horizon over the past four years, according to a recent survey.

Elsewhere in the inquiry on Thursday, Mr Read said he was “surprised” at the “scale” of interest from the police, after learning that 33 investigations into branches were being carried out in June this year.

The current boss was asked about the organisation’s response to the fact that 22 police forces were investigating Post Office branches.

Mr Nick Read said: “I think there was some surprise at the scale of requests in terms of the 22 law enforcement agencies and the 33 requests.

“I think we were of the opinion that it was in the ones and twos in terms of requests for information… the primary discomfort was the size and the number of the requests that were coming forward.”

The inquiry heard that the police were “requesting or awaiting Horizon-based evidence” for their investigations.

Mr Read told the inquiry that its internal investigations team was “massively stretched” at the time that the police were engaging with the business.