The Home Office is reviewing its archives to see if any files exist on Paul Cleeland, who has been fighting to clear his name of murder for 47 years.
Damian Collins MP sought answers from the Home Office after Cleeland raised questions about an archive from a 1990s inquiry by retired judge Sir John May.
Cleeland, from Kent, served 26 years in prison for the murder of Terry Clarke in Hertfordshire in 1972.
His long-running legal battle has been continuing in the Administration Court.
The archive catalogue included a documentary given to Sir John by the BBC in 1992.
The programme - Who Killed Terry Clarke? - was provided as part of the Royal Commission on Criminal Justice, which followed a series of high-profile wrongful convictions.
The documentary stated that a copy of the film had been accepted by the inquiry but it is not yet known whether Sir John took any other evidence on Cleeland's case.
Cleeland's campaign has seen two failed appeals and ongoing proceedings against the Criminal Cases Review Commission - which has not commented.
After Folkestone and Hythe MP Mr Collins submitted questions, Home Office Minister Kit Malthouse said: "A review of any Home Office file holdings on this subject is currently being undertaken. It would not be appropriate to comment further while legal proceedings are ongoing."
Mr Collins said: "I think it's important that Paul Cleeland is aware of any Home Office files that exist and which are relevant to his application to have this case referred back to the Court of Appeal.
"I'm pleased that the Home Office are now conducting a review to see if they have any such files.
"I hope that the results of this review will be made available to Paul Cleeland and his lawyers."