The FBI has released almost 500 never before seen files on OJ Simpson that reveal more details about the infamous case.

The tranche was published Friday and largely covers the investigation into the 1994 murders of Simpson’s ex-wife Nicole Brown and her friend Ron Goldman.

Simpson was cleared of criminal charges in 1995, following a high profile trail which captured the nation’s attention.

He was later found civilly liable and ordered to pay the victims’ families $33.5 million. He maintained his innocence until his death in April aged 76.

The secret documents show the lengths the FBI went to to keep their findings under wraps.

‘Due to the intense media interest in captioned matter, and the potential prejudicial impact that public dissemination could have on pending criminal proceedings the following information should be handled on a strict need to know basis, and should not be disseminated outside the FBI,’ one internal memo published states.

The files also reveal the huge effort investigators put in to identify the shoes worn by the killer.

LA homicide detectives determined the footwear to be a pair of rare Bruno Magli shoes, with agents flying to the manufacturer in Italy in a bid to glean more information.

Agents dispatched to the factory were briefed, ‘under no circumstance should the interviewing agents mention that this investigation concerns OJ Simpson or the homicide investigation in Los Angeles, California’.

Other details include lists of materials found at the scene which were sent for DNA testing.

Two rambling letters dated June 1994 are also among the documents, written by an individual claiming to have visions about the killings.

‘I can’t sleep at night. The dreams that I have, where pieces of the puzzle fall into place. And the ultimate dream that the killer is still out there and is after me,’ one reads.

The FBI publishes records it keeps on individuals following their death.

The tranche was published as ‘Part 01’, though it is unclear if any more documents will be forthcoming.

Simpson became one of the most infamous figures in America after he was charged with the 1994 murders.

He became the star of the ‘Trial of the Century’ which gave the world its first glimpse at reality TV.

Viewers were gripped for the 11 month trial, which featured several outrageous twists and turns.

Judge Lance A. Ito’s decision to allow a single camera in his courtroom arguably affected the case and provided daily salacious soundbites and memorable clips from grandstanding attorneys and emotional witnesses.

Defense attorney Johnnie Cochran delivered the one of the most notable lines during the trial in his closing argument that has carried into pop culture: ‘If it doesn’t fit, you must acquit’.

He was referring to the gloves that were found at the crime scene that he said couldn’t have been OJ’s because his hand was too big.

Simpson, a former football running back who played 11 seasons mostly with the Buffalo Bills, reinvented himself as an actor before Brown and Goldman’s murders.

Although cleared of the killings, his reputation was tarnished forever and the latter part of his career was marked by a series of seedy ventures.

In 2008 he was jailed for armed robbery in Nevada and served nine years in prison.

He again maintained his innocence and claimed that he was just trying to retrieve sports memorabilia taken from him.

Simpson never admitted to the killings an died owing the victims’ families more than $100 million.