Was the untimely passing of Whitney Houston caused by drug dealers?

After Whitney's tragic death last February, coroners revealed a month later that it was caused from drowning in a bathtub and the "effects of atherosclerotic heart disease and cocaine use." But Paul Huebl, an investigator in the case, is now claiming that it wasn't a drug overdose, but drug dealers that killed her. He's claiming to have video evidence which proves this, according to the National Enquirer.

Is this just a guy on an insensitive hunt for publicity? Or is there any truth to it?