The "last breaths" of a man gunned down outside a bar have been shown on television as police announced a £40,000 reward to catch his killer.

Marvin Couson was 26 when he was shot in front of up to 300 people outside a London nightspot in 2002, causing a brain injury that left him in a vegetative state.

He spent the next 13 years "in pain, in suffering" according to his family, before he died in August, just months from his 40th birthday.

The BBC's Crimewatch programme on Monday broadcast phone footage taken by his sister Margaret at his bedside in hospital just minutes before he passed away.

She told the programme: "I feel people need to see that this man, this innocent man - completely innocent - suffered in this way until he took his last breaths because someone took a gun and shot him."

Police were called to Lime in London Bar, or Lime Bar, in Curtain Road at 3.40am on May 12 2002, after reports gunshots had been fired. The bar is now the Queen of Hoxton pub.

Mr Couson, a father of two, of Dallington Road, West Norwood, was found lying on the ground with a bullet wound to his chest, police said.

The Crimewatch reconstruction showed that a gun was fired in the bar and people fled outside. A friend confronted two men driving past in a T-reg red or burgundy Ford Fiesta and as he did so a second shot was fired, hitting Mr Coulson.

He was taken to the Royal London Hospital with critical injuries to his heart and other internal organs before being transferred to the Royal Hospital for neuro-disability. He died in hospital on August 8 last year.

A man was arrested on May 23 2002 in connection with the shooting, but released with no further action.

Police said it was not clear if the shot came from inside the car but they want to trace the men inside. They said 200-300 of the 600 people at the bar for a party had fled into the street before the shooting happened.

Detective Chief Inspector Noel McHugh from the Metropolitan Police's homicide and major crime command said: "Tonight we have announced a large reward in the hope that it will encourage someone to come forward.

"Marvin's shooting happened many years ago but you would remember if you were there that night and were one of those who fled in panic as shots were fired inside the bar.

"We need to speak to everyone who was there that night. I remain concerned some people may have a misguided sense of loyalty and are possibly protecting those who carried out this attack.

"Marvin should have celebrated his 40th birthday in November. Instead he spent 13 years in a hospital bed unable to do anything for himself before tragically succumbing to his injuries."