Hollywood Publicist Murder Tipster Sues Where's My Reward?!

10/3/2011 1:35 PM PDT

Tipster in Hollywood Publicist Murder Sues -- WHERE'S MY REWARD?!

The man who claims he led police to the person accused of gunning down Hollywood publicist Ronni Chasen claims he never got his $125,000 reward -- and now he's suing to get his money.

The tipster -- who only identifies himself as John Doe -- claims a bigshot publicist named Michael Levine offered a $25k reward for information leading to the identification and arrest of Chasen's killer. He also claims Palm Springs Film Festival honcho Harold Matzner offered $100k.

According to his lawsuit, filed today in L.A. County Superior Court, the tipster claims he called "America's Most Wanted" after learning of the reward offers and provided the name of a man named Harold Martin Smith ... who cops eventually concluded DID in fact murder Chasen.

Chasen was gunned down in Beverly Hills on November 16, 2010. Smith was cornered by cops at a Hollywood apartment complex weeks later ... but committed suicide when officers tried to confront him.

In his lawsuit, John Doe says the Beverly Hills Police Department can back up his claim that he is the "sole" tipster responsible for the identification of Chasen's killer -- and says the PD even put it in writing in a letter to his lawyer.

TMZ spoke with Levine, who tells us the claims against him are "totally false" ... adding, "I never arranged for a reward fund. I offered to call some friends, but was told by the family that the Palm Springs Film Festival was handling the reward."