The man who claims to have provided the tip leading police to publicist Ronni Chasen's murderer is suing for $125,000 in reward money he says he's owed.

John Doe sued Harold Matzner, chairman of the Palm Springs Film Festival and publicist Michael Levine in L.A. Superior Court Monday, claiming breach of contract, promissory estoppel and fraud.

The suit was first obtained by TMZ, and demands the $100,000 reward promised by the Palm Springs festival, and a $25,000 reward offered by Levine.

The informant says that he called in to the television show America's Most Wanted with information on the killer, which eventually led police to Harold Martin Smith.

But in an interview with TheWrap, Matzner said he still was unconvinced that Harold Martin Smith was Chasen's murderer, and he doesn't believe there is enough evidence to justify dispensing the reward.

All we have is a gun. We don't have anything else, he told TheWrap. And I'm sorry that's where we are.

Smith was being approached by police officers for questioning when he shot himself dead. The reward was offered for information leading to the arrest and conviction of Chasen's murderer.

In July, police told TheWrap that Chasen was murdered with a gun stolen from a police officer, and officially closed the case.

The suit claims that the Beverly Hills Police Department can vouch that the plaintiff is the sole tipster in the case.

Matzner said that despite declaring the case closed, Beverly Hills police have offered him no hard evidence that Smith shot Chasen.

It's not enough with a case of this import to simply declare it closed without revealing the evidence that supports that conclusion, said Matzner. All we have is the gun. I can't get anything else from the Beverly Hills police department. That's not enough. If they have something that puts him at the scene with the gun, they need to share it.

The BHPD concluded that Smith was responsible for Chasen's murder, and had acted alone. The department's conclusion has been met with skepticism among many who believe that the full story surrounding Chasen's death was never revealed.

Chasen was shot to death on November 16, 2010, while returning home from a party for the movie Burlesque.