Investigators believe knife found at O.J. Simpson's Rockingham estate is too small to be the murder weapon... but tests will take at least three weeks

The knife reportedly found at O.J. Simpson's former estate likely is not connected to the killings of his ex-wife and her friend, a law enforcement official said - but it will take at least three weeks to know for sure.

Investigators are examining the knife for DNA or other material that could possibly link the weapon to the 1994 murders of Simpson's ex-wife and her friend.

But results aren't expected for at least three weeks, Capt. Andy Neiman said on Wednesday.

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Test results on the knife aren't expected for at least three weeks, Capt. Andy Neiman (pictured) said on Wednesday. However, an law enforcement official says detectives doubt it is connected to the killings

Meanwhile, a law enforcement official with knowledge of the investigation told The Associated Press that detectives doubt the knife is connected to the killings.

The official said the knife is commonly used among gardeners and was too small to make the wounds that killed Nicole Brown Simpson and Ron Goldman.

The official was not authorized to publicly discuss the investigation and spoke only on condition of anonymity.

Both Simpson and Goldman had deep gashes to their necks, in addition to a number of other extensive knife wounds.

The weapon used in the killings has been a mystery for decades. Other knives have surfaced during the case, but they were not linked to the crimes.

O.J. Simpson, center, reacts as he is found not guilty of murdering his ex-wife and her friend in 1995, as members of his defense team, F. Lee Bailey, left, and Johnnie Cochran Jr., right, in court in Los Angeles

Investigators are examining the knife for DNA or other material that could possibly link the weapon to the 1994 murders of Simpson's ex-wife Nicole Brown Simpson (left( and her friend Ron Goldman (right)

On Friday, Los Angeles police revealed that they were examining a knife reportedly found at Simpson's estate years ago.

Police said a construction worker gave the knife to an officer working as a security guard at a filming location. The officer then kept the knife for a number of years, police said.

Trent Copeland, an attorney who represents the officer, said his client retired in 1998 and that the construction worker gave him the knife in 2002 or 2003 - well after a jury found Simpson not guilty of the murders.

Copeland said the officer, George Maycott, immediately called LAPD to report the knife.

'Someone put him on hold, that person came back several minutes later, said he spoke to a supervisor who said, ‘Double jeopardy is attached to this case, O.J.'s been acquitted. If that knife had blood on it there's really nothing we can do about it, so we don't want anything to do with this,' ' Copeland said.

Pictured, a Buck brand folding knife of the Buck brand, similar to the one described by LAPD officials after the discovery at Simpson's estate

Los Angeles Police Capt. Andy Neiman takes questions from reporters during a new conference at police headquarters in downtown Los Angeles on Friday

Maycott then kept the knife in a toolbox for the next 13 years or so.

'He was not this sort of bumbling keystone cop who cavalierly decided he would take what could have been a pivotal piece of evidence and put it in his bag,' Copeland said.

'He knows that he did exactly what any diligent professional officer would have done and that is you call LAPD immediately — and that's what he did.'

The bodies of Brown Simpson and Goldman were found stabbed multiple times outside her home on June 12, 1994. 

The discovery led to the so-called 'Trial of the Century' - currently the subject of a ten-part FX series The People V OJ Simpson: American Crime Story - in which Simpson was represented by a team of high-profile attorneys led by the flamboyant Johnnie Cochran.

Simpson (pictured in 2013), who has always maintained his innocence, is now serving a sentence of nine to 33 years in a Nevada prison for a 2007 armed robbery and kidnapping conviction

Crews demolish the former home of O.J. Simpson, in 1998, in the Brentwood area of Los Angeles. Detectives are investigating a knife purportedly found some time ago

A jury acquitted Simpson in 1995 after deliberating for only four hours.

But in 1997, a civil court jury found him liable for the killings and awarded $33.5 million in damages to the victims' families.

Simpson, who has always maintained his innocence, is now serving a sentence of nine to 33 years in a Nevada prison for a 2007 armed robbery and kidnapping conviction in which he tried to retrieve football memorabilia.

He is eligible for parole next year.