Writer and producer of popular TV shows such as The Avengers, The Professionals and The Persuaders!The writer and producer Brian Clemens, who has died aged 83, was responsible for hundreds of hours of escapist television entertainment, including such enduringly popular programmes as The Avengers and The Professionals.Even though he did not create The Avengers, Clemens was involved in the show from its first episode, in 1961, which he co-wrote.