Former WCW wrestler Silver King has died after collapsing during a fight in London.

The 51-year-old Mexico native, whose real name is César Barrón, was competing at a Lucha Libre wrestling show at the Roundhouse in London on Saturday evening when he died, organizers of the event confirmed.

"Lucha Libre AAA Worldwide joins the grief that the Luchistica family has for the death of César Cuauhtémoc González Barrón 'Silver King'," Lucha Libre wrote on Twitter.

Barrón was reprising the villainous role of Ramses for the event, which he previously played in the 2005 Hollywood comedy "Nacho Libre" alongside Jack Black. He is believed to have died from a heart attack, according to industry reports.

The London Ambulance Service reported that two ambulances, an advanced paramedic and an incident response officer were dispatched to the venue after being called at 10.21pm. They stated that Barrón died at the scene, however.

The Roundhouse confirmed that the incident had taken place and said the circumstances surrounding Barrón's death were being investigated.

"Our thoughts and condolences are with his family, friends and all the Lucha Libre team," the venue said in a statement according to the UK's Press Association.

London's Metropolitan Police stated that they are treating Barrón's death as "non-suspicious."

WWE, the US professional wrestling organization, said in a statement that it was "saddened" by the news of Barrón's death. "WWE extends its deepest condolences to Silver King's family, friends and fans."

Tributes also flooded in from fellow wrestlers. El Hijo del Santo, a fellow Mexican wrestler, wrote on Twitter: "I deeply regret the death of my great rival and partner in so many battles. He went as he wanted: fighting."

Sean Waltman, a former WWE star, said: "It was an honor to have been friends and shared the ring with the great Silver King.

"He truly was one of the greats and I'm heartbroken to learn of his passing."

Eric Bischoff, the former president of the World Championship Wrestling (WCW) organization, added: "I am saddened to hear about the passing of Silver King. Like so many of the great Luchadores that helped Americans appreciate Lucha Libre and make Nitro the success it was, he will be missed. Thank you and RIP."

Barrón grew up in the Mexican wrestling family; his father, Dr Wagner, was a famous Luchador in the 1960s until a car accident halted his wrestling career. His brother also competed as a wrestler under the name, Dr. Wagner Junior.

Barrón achieved worldwide success and performed for the WCW between 1997 and 2000, regularly appearing on its TV show WCW Monday Nitro.

His highest-profile fight was for the WCW Cruiserweight Championship against Juventud Guerrera in 1998, which he ultimately lost.