O.J. Simpson is secretly selling the knife used to kill his former wife Nicole Brown Simpson and her friend Ron Goldman, according to a report from the National Enquirer.

According to a source the newspaper is quoting, Simpson is asking $5 million.

"(O.J. is) looking for a strictly cash deal so that the money can be deposited in offshore accounts and can't be traced directly to him," the National Enquirer reported a source close to the ex-football star and actor told the paper.

Simpson has long denied owning the knife, having been found not guilty of the murders of Goldman and his wife, who were slashed to death outside Nicole's Los Angeles home on June 12, 1994. His "trial of the century" was one of the most sensational in US history.

A civil jury in 1997 found Simpson liable for the deaths and ordered him to pay $33.5 million in damages to the murder victims' families.

The Enquirer reported - again from a source close to Simpson - that the knife is presently stashed in the Bahamas, where it awaits the highest bidder.

"It's not just about the money," the source reportedly told the paper. "O.J. will get sick satisfaction from putting one over on the cops and Ron Goldman's family. He'd love to think he's outsmarted them."

Simpson is currently serving up to 33 years in prison for a 2007 armed robbery in which he claimed he was trying to recover his own sports memorabilia.