Picture: Lucha Libre World/Twitter

London - A Mexican wrestler known as Silver King died in the ring during an appearance in London, the venue confirmed on Sunday.

"Last night Silver King sadly lost his life during an event at the Roundhouse," said a statement posted on Twitter by the venue in the north London borough of Camden.

"At this stage the details are still being investigated so we don't have more information we can share," it added.

The 51-year-old, whose real name was Cesar Cuauhtemoc Gonzalez Barron, was a star on Mexico's Lucha Libre wrestling scene.

He may have suffered a heart attack, according to media reports.

A video circulating on the internet shows Barron having difficulty getting up during an exhibition fight. Despite the referee's request, he finally lies flat on the floor.

Eyewitnesses told the BBC that there was some confusion as to whether the incident was part of the show.

Barron began his career in the 1990s for World Championship Wrestling (WCW) in the US. He became famous for playing the villain Ramses in the film "Nacho Libre."