Los Angeles police are examining a knife found buried some time ago on the property of former NFL star OJ Simpson.
Simpson was acquitted in 1995 of the double homicide of his ex-wife, Nicole Brown Simpson, and her friend, Ronald Goldman, in a trial that was played out on television around the world.
Brown and Goldman were stabbed to death, but a murder weapon was never retrieved.
On Friday, the LAPD confirmed that someone claiming to be a construction worker had found the knife and that it had only recently been made available to police, with a report from entertainment website TMZ claiming that it may have been discovered during the demolition of Simpson's former Rockingham home in 1998.
TMZ reported that the knife had been passed on to a former LAPD officer, who held onto it until earlier this year.
"The person we received this knife from is a retired LAPD officer who retired in the late '90s," Captain Andrew Neiman told reporters, before cautioning that the story could yet turn out to be false.
Neiman added that the LAPD had learned about the possession of the knife "within the last month" and were now working to "determine whether it's evidence or not".
Neiman did, though, appear to cast some doubt on the apparent discovery.
"I would think that an LAPD officer would know that anytime you come into contact with evidence that you should, and shall, submit that to investigators," he added.
"So I don't know what the circumstances are, why that didn't happen - if that's accurate - or if this whole story is bogus from the get-go involving a variety of people."
The knife will now be examined for hair and fingerprints and ultimately DNA and biological evidence. However, under US law Simspon would not be able to face a retrial, having previously been acquitted of the crime.
Neiman added: "I'm not a legal expert but my understanding is that the double jeopardy [law] would be in play here. We would not charge Mr Simpson because he has been acquitted."
Simpson is currently serving a prison sentence in Nevada for a number of unrelated felony charges, including armed robbery and kidnapping, stemming from an arrest in 2007.
Interest in the 1995 case has been reignited following a recent hit television show titled 'The People vs OJ Simpson: American Crime Story', which was first aired in the United States.