The killing is said to have taken place in the Netherlands over two decades ago
Former panellist on TV quiz show Eggheads, CJ de Mooi, has been arrested in connection with an alleged killing over 20 years ago.
He was detained under a European arrest warrant at Heathrow Airport on Wednesday.
De Mooi, who lives in Monmouthshire, Wales with his civil partner Andrew Doran, is wanted over an alleged killing in the Netherlands.
The suspect, 46, was held under his real name Joseph Connagh and will appear at London's Westminster Magistrates' Court later.
De Mooi claimed in his autobiography CJ: The Autobiography of CJ De Mooi: My Journey From the Streets to the Screens he punched a man who approached him with a knife and threw him into a canal in Amsterdam in 1988.
In the book, which was published in September 2015, he wrote: "He caught me on the wrong day and I just snapped. I've no idea what happened to him."
De Mooi became a panelist on Eggheads in 2003 after winning a series of game shows.
The programme features five quiz champions competing as a team against different challengers.