An investigation has been launched into the policing of Peter Sullivan, who was wrongly convicted of murder in 1986.
Mr Sullivan claimed that police blackmailed him into confessing to the killing of florist Diane Sindall, 21, in Wirral, Merseyside.
He was jailed for 38 years - the longest miscarriage of justice in British history.
Mr Sullivan, now 68, was only freed when DNA matching somebody else was found on crime scene samples in 2023.
He told a BBC interview last November that Merseyside Police threatened to charge him with "35 other rapes" if he did not confess to the killing of Ms Sindall.
"They threw a blanket over the top of me and they were hitting me on top of the blanket with the truncheons to try and get me to co-operate with them," he added.
As a result of the comments, The Independent Office for Police Conduct (IOPC) has launched a probe into the police's conduct at the time of his arrest.
IOPC Director Amanda Rowe said: "Mr Sullivan was a victim of one of the worst miscarriages of justice this country has ever seen. Our thoughts are with him as he continues to rebuild his life.
"In light of the significant impact this has had, as well as the severity of some of the allegations contained in the complaint, it is important for these matters to be independently investigated.
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"The fact this took place almost 40 years ago poses substantial evidential challenges, however we will do all we can to progress our inquiries as quickly as we can, while taking all appropriate steps to ensure this does not hinder the ongoing investigation by Merseyside Police into the horrific crime against Ms Sindall."
(c) Sky News 2026: Investigation launched following case of man who was wrongly jailed for 38 years
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