Melbourne radio station Triple M is on trial accused of defaming an Olympic cyclist.

Mark French is suing Triple-M, for comments made on its program The Cage in 2004.

The Victorian Supreme Court heard the broadcast labelled French a drug cheat, who had dobbed in his teammates to authorities.

The court heard French was also called "un-Australian" and "a dirty stinking dobbing cyclist."

French's lawyers told the court, their client was a highly regarded professional cyclist who had found the broadcast very hurtful.