The family of a man who died after being restrained by bouncers outside a bar in London are offering a £1,000 for any footage of the incident.
Adam Hird, from Epping, collapsed outside Club No.65, in Vauxhall, in the early hours of 15 June and died two days later in hospital.
Police were called to reports that he was being restrained by security staff at 3.20am and officers found him collapsed when they arrived.
Further tests are being carried out after a post-mortem in June was inconclusive.
Mr Hird, a travel agent, was engaged at the time of his death and was hoping to become a commercial pilot.
His family released a statement saying the 30-year-old was “full of life, kind, gentle and funny”.
It continued: “He loved traveling and new experiences and had visited some of the most far flung and often dangerous countries around the world and we often worried about him when he was away.
“We never imagined that this could happen, right here, so close to where we live, where he should have been safe. We are deeply shocked and distraught at what has happened to Adam.”
Detectives and Mr Hird’s family are appealing for a woman believed to have filmed the events on her mobile phone to come forward.
The woman was described as tall, slim and in her 20s, with blonde hair in a ponytail.
She was wearing shorts and her phone was said to be a “flip phone”.
Det Insp Sharon Marman, from the Metropolitan Police, said: “I would like to reassure this woman that she is not in any trouble and that she can contact the police with the confidence that she will be treated with the utmost sensitivity.”
A statement from Mr Hird’s family offered a reward of £1,000 to anyone providing footage.
It added: “We sincerely ask that anyone who witnessed or recorded the incident please contact the police.”
Four men arrested in connection with the investigation have been bailed.