Carole Baskin's missing husband's will was "100 percent a forgery", according to a sheriff in Florida.
As depicted in Tiger King, Don Lewis mysteriously disappeared in 1997 and was declared dead five years later, with Carole inheriting all his money.
Her rival Joe Exotic, who is in prison after hiring a hitman to kill Carole, suspects she had something to do with his disappearance, which she has always denied.
Hillsborough County Sheriff Chad Chronister claimed on Tuesday that two different experts have said Don's will is forged.
Chronister told CBS station WTSP: "We knew that before because the girl who came forward and said, 'Hey, I was forced to witness and say that I witnessed this signature.'
"The problem was the statute of limitations had already expired. The will had already been executed at that point."
He said that the "only reason" legal action hasn't been taken is because of the statute of limitations' expiration.
Chronister added: "There's no recourse. A judge deemed it valid, so the civil side of it would be execution of the will, the disbursements of the funds is one thing.
"But then you have the criminal side of it, it's unable to be prosecuted because of the statute of limitations."
He said the will "certainly cast another shadow of suspicion" on Lewis' disappearance.
Chronister continued: "Investigators have some great leads, they're working through them. I hope something pans out."
Mirror Online has contacted Carole Baskin for comment.
The judge has ruled that Joe's transfer of the zoo land to his mother and Jeff was fraudulent, according to court documents obtained by TMZ.
As Carole never got the money she won in a $1million judgment against Joe and his mum many years ago she has been awarded the land to recover some of what she is owed.