One of the Cronulla Sharks' longest-serving players in the modern era has added to the legal drama surrounding the club after joining ex-teammates in suing the premiers over the supplements scandal.

Anthony Tupou, who was contracted at the Sharks until as recently as last year, has joined almost half of Cronulla's 2011 squad in instigating legal action against the NRL club.

It only adds another layer to the legal circus engulfing the Sharks, who were previously asked to mediate a $2.4 million claim from former five-eighth Todd Carney over his dismissal from the club.

Tupou joins a host of other teammates who have engaged Shine Lawyers to represent them.