A Hollywood private detective is claiming that Whitney Houston was murdered, and has allegedly uncovered CCTV footage that proves the superstar was the victim of an attack by two men who were sent to collect a debt for drugs.

Paul Huebl has made the sensational claims in the gossip publication, National Enquirer. He said: "I have evidence that points to Whitney being a victim of high-powered drug dealers who sent thugs to collect a huge debt she owed for drugs."

He alleges that the day before her death Whitney was heard to say “I’m tired of this s***,” after taking a delivery of cocaine from the dealers.

Huebl also believes that despite a coroner's report that claims there was no foul play involved, the signs on her body tell a different story.

He said: “Whitney’s body shows classic defence wounds that would have occurred while she was battling for her life.”

Huebl details the injuries and how they point to a struggle just before her death in the latest edition of magazine, which went on sale in the US today (December 27).

He also adds that there were two mystery men seen trying to blend in with Whitney's entourage at the Beverly Hilton hotel, where she stayed in the days leading up to her death, and that on the day she died there was a 45-minute 'gap' where her alleged killers slipped in to her room and were caught on camera.

Huebl claims to have discovered the new information through a network of informants and says he is now handing the evidence over to the FBI in an attempt to have the case reopened.

Huebl runs a private investigation firm, Paul Huebl Investigations. The company is licensed in Arizona and California.

Watch Whitney Houston sing her comeback single, 'Million Dollar Bill' on The X Factor below: