The 21-year-old socialite was forced to quash the allegation after an American, known only as Ben, posted naked pictures of Sir Bob's daughter on the internet.
According to The Sun, he alleged that he had a one night stand with the Ultimo model in Los Angeles last November and claimed that they took a friend's car, bought some needles to inject the drug, then went to her room and "did it every way possible".
"Things got hot and heavy and before I know it we're naked. We had a naked dance party on her bed," he said. The pair then reportedly drove to Hollywood's Scientology Centre for purification in the sauna and exercise room.
A friend said that Peaches was "spitting fury" over the claim, while a spokesman said: "The allegations that our client was carrying and injecting heroin are denied, our client having just consumed alcohol with the other individual leading to the 'highs' described and portrayed in the photographs."