Tyson Beckford -- Sex Tape Being Shopped

A sex tape which is said to feature male supermodel Tyson Beckford is being shopped around the adult entertainment community ... TMZ has learned.

Sources tell us ... the seller insists the 45-minute tape shows the former Polo model pleasuring himself during a recent Internet video chat with a female model.

We're told ... during the chat session, Tyson makes references to some of the movies he's appeared in ... and talks about some of his co-stars.

Sources say Beckford also reveals one of his pet peeves -- being mistaken for Tyrese Gibson.