Former British heavyweight boxing champion James Oyebola was shot dead in a nightclub after asking a group of men to stop smoking, a court heard today. Prosecutor Jeremy Donne told the Old Bailey that the Nigerian-born boxer died after the "senseless" shooting at the Chateau 6 club in Fulham, west London, in July 2007.

He never regained consciousness after being hit in the neck and leg and died in hospital four days later when doctors switched off his life-support machine. The boxer won the British heavyweight title in 1994 and the bronze medal at the 1986 Commonwealth Games in Edinburgh, where he lost to Lennox Lewis in the semi-finals.

Four men are on trial for his murder: Cyle Carth, 18; Dean Francis, 24; Rene McKoy, 20 and Kanyanta Mulenga, 23, all from south London. They deny murder and affray.

"Probably all unlawful killings are senseless but this unlawful killing was particularly senseless," Donne told the court. "James Oyebola had become involved in a dispute over smoking inside the club.

"In the course of the resulting confrontation with these four defendants, one of them produced a gun and fired four bullets, two striking the hapless Mr Oyebola." CCTV footage suggests Mulenga fired the shots that killed Oyebola and then fled the club, Donne added.

"It is the prosecution case that all four defendants knew that a gun was being carried by one of their number and that it might be used if and when the need arose," he said.

"It follows that, by remaining with the gunman and becoming involved in the confrontation each man is responsible for his death." The venue's DJ James Cornwell saw Oyebola struggling with three men, describing it as "like a giant against kids", the prosecutor added. The DJ saw the gunman fire several shots before the crowds ran for the exit.

Witnesses said Oyebola had been "pleasant, calm (and) happy" before the shooting. He had been asking people to stop smoking in the courtyard. Some revellers assumed he was a bouncer.

The court heard that the former boxer was friends with the owner of the club and his son. The trial continues.