More than 700 post office managers have been fined after faulty accounting software made it appear money was missing from their sites.
Many of them were imprisoned, lost their livelihoods and reputations, and some even committed suicide.
The investigation aims to establish the extent of the Post Office’s failures and liability, and to make recommendations for the future.
The case was described by the Criminal Cases Review Commission as “the most widespread miscarriage of justice ever seen”., external and represents the largest series of wrongful convictions in British legal history.”
Ms Knight, who was cleared of false accounting in 2013, said she had felt isolated and hopeless.
“Alan Bates, bless him, believed in the truth and he wasn’t going to give up.
“Our hero Alan was making a lot of waves alongside my time in court,” she said.
“Honestly, I owe this man my life because I don’t think if he hadn’t made waves I would have been criminally convicted.”