Former Post Office boss Paula Vennells will give evidence to the next phase of the inquiry into the Horizon IT scandal.
She served as chief executive from 2012 to 2019, and has faced questions about why hundreds of subpostmasters were wrongly convicted of fraud and false accounting under her watch.
Scrutiny grew after she was depicted in the ITV drama Mr Bates Vs The Post Office – and she gave back her CBE after the programme sparked public anger.
When she returned her honour, Ms Vennells had said: “I have so far maintained my silence as I considered it inappropriate to comment publicly while the inquiry remains ongoing and before I have provided my oral evidence.
“I now intend to continue to focus on assisting the inquiry and will not make any further public comment until it has concluded.”
Alan Bates will also be giving evidence to the inquiry when it resumes in April – as well as Lord Arbuthnot, who campaigned on behalf of subpostmasters during his time as an MP.
Former business secretary Sir Vince Cable and current Liberal Democrat leader Sir Ed Davey, who previously served as postal affairs minister, will also testify.
The scandal, which was ongoing from 1999 until 2015, represents one of the largest miscarriages of justice in UK legal history and more than 100 subpostmasters have had their convictions quashed by the Court of Appeal.
Many more are yet to be cleared and the government has come under fire for the compensation awarded to victims.
Glitches in the Horizon IT system used by the Post Office meant money looked as if it was missing from many branch accounts when in fact it was not.