Malcolm-Jamal Warner, the actor, who has died aged 54, was cast as Theo Huxtable in the sitcom The Cosby Show at the age of 13, and over the course of some 200 episodes became one of US television’s best-known teenagers.

Mr. Warner, who played the only son of Bill Cosby’s character on the beloved 1980s sitcom, drowned in Costa Rica.

Malcolm-Jamal Warner as Theo Huxtable on The Cosby Show Credit - NBCUniversal via . I n the final episode of The Cosby Show, Dr. Heathcliff Huxtable is beamin