A man who was stabbed to death close to Brixton tube station in south London was filming a music video when he was killed, onlookers said.

Despite the efforts of emergency services, the victim – who was aged in his early 20s – was pronounced dead at the scene at around 8.45pm on Wednesday.

A 24-year-old passer-by told the PA news agency: “I didn’t see the stabbing but I saw him take his last breaths.

“I saw him on the floor, there were loads of police officers around him.

“People around said they were making a music video and an argument broke out out of nowhere and a man produced a machete and stabbed this guy multiple times.”

He continued: “A girl was slashed as well. They said it was the victim’s girlfriend when she tried to intervene.”

An onlooker told the BBC the incident had involved a number of high-end cars, including a Lamborghini, a Ferrari and a black Range Rover and two quad bikes.

The onlooker told PA: “I didn’t see a Lamborghini or anything like that – maybe they had been moved – but I saw the quad bikes.”

The Metropolitan Police said on Wednesday evening: “(The victim’s) next of kin have been informed. Formal identification has not taken place and a post-mortem examination will be arranged.”

Police said a man was arrested nearby on suspicion of causing grievous bodily harm.

Detectives from the Specialist Crime Command had been informed.