Diamond: 'Gosselaar was on steroids'

Dustin Diamond has claimed that his ex-Saved By The Bell co-star Mark-Paul Gosselaar used steroids.

The 32-year-old, who played Sam 'Screech' Powers on the US sitcom, previously announced that he is writing a tell-all book that details the alleged drug and sex habits of his former Bell castmates.

Diamond wrote in Behind The Bell - which is released in the US on Tuesday - that Gosselaar (who played Zack Morris) used steroids prior to filming the short-lived 1994 spinoff Save By The Bell: The College Years, according to Us Weekly.

"He suddenly exploded with manliness, loading 25 pounds of muscle on his once-scrawny frame in, oh, about a month," he said.

Diamond also suggested that the cast engaged in drug use and that he could "smell a certain smoke, wafting from the crack [underneath the dressing room doors]".

Gosselaar, 35, has dismissed the allegations, saying: "We weren't in rehab and Mr Belding wasn't my crack dealer."

Gosselaar earlier said that he couldn't "wait" for Diamond's book to be published.