A former police officer is under criminal investigation following the wrongful conviction of Andrew Malkinson, who spent 17 years in jail over a rape he did not commit.
The police watchdog has announced four retired officers from Greater Manchester Police (GMP) are being investigated for gross misconduct.
The Independent Office for Police Conduct (IOPC) said one of the officers had also been placed under criminal investigation for misconduct in a public office and perverting the course of justice.
Mr Malkinson, 58, was jailed for rape in 2004 until his conviction was quashed by the Court of Appeal last year.
The IOPC is now investigating complaints by Mr Malkinson about GMP and its investigation leading to his imprisonment.
The watchdog is examining whether police followed the appropriate processes during the identification of Mr Malkinson as a suspect – whether witnesses were offered any incentive to provide evidence, the alleged failure to disclose information that may have helped Mr Malkinson’s defence at his trial and the handling and disposal of items of evidence.
Catherine Bates, the regional director of the IOPC, said: “Mr Malkinson is a victim of one of the worst miscarriages of justice in British history.
“We continue to work hard to ensure his complaints are thoroughly and independently investigated.
“Following a detailed review of evidence spanning a period of more than 20 years, we have now informed four retired GMP officers that they are under investigation for potential gross misconduct.
“One of the officers has also been notified that they are under criminal investigation for potential misconduct in public office and perverting the course of justice in relation to their actions during the police investigation and subsequent trial.
“Our investigation team continues to work hard to conclude our investigation as soon as reasonably possible while ensuring our inquiries do not prejudice separate criminal matters linked to the crime Mr Malkinson was wrongly convicted of.
“We will continue to keep Mr Malkinson and GMP updated on our progress.”
The IOPC added that serving an officer with notice they are under investigation does not necessarily mean that disciplinary proceedings or criminal charges will follow.
At the end of its investigation, it will determine whether there is an indication that anyone serving with the police may have breached the standards of professional behaviour or if the case should be referred to the Crown Prosecution Service.
Before his conviction was quashed in July 2023, Mr Malkinson twice applied for his case to be referred for appeal by the Criminal Cases Review Commission (CCRC), but was turned down.
Mr Malkinson was eventually released from prison in December 2020.
Thousands of convictions are now being reviewed in the wake of his case.
The CCRC has been told to look back over all cases which have the “possibility of DNA opportunities”.
A review found delays and failings in Mr Malkinson’s case, which spanned years. It said they demonstrated a “deep-seated, system-wide, cultural reluctance, which starts right at the top in the Court of Appeal, to acknowledge our criminal justice system will on occasion make mistakes, that entirely innocent defendants will sometimes be convicted”.
The CCRC admitted to failing Mr Malkinson and offered an “unreserved apology”.
