A Metropolitan Police officer is under criminal investigation for potential assault after Sex Education star Reece Richards claimed he was injured during a wrongful arrest in west London.

The actor wrote in a post on Instagram that as he was returning home after starring in West End musical Hairspray on 4 September, he was sprayed with an incapacitating liquid, thrown to the ground and kicked by officers who had mistaken him for a suspect.

The Independent Office for Police Conduct (IOPC) said it had advised one officer "they were under criminal investigation", as well as also being investigated for potential gross misconduct.

Another officer is being investigated for potential misconduct, it added.

Netflix star Richards said he had witnessed a car crash after which two men had fled on foot, and he had then pointed to police where they had run.

However, he wrote that the four officers had instead restrained him by sitting on him, which worsened existing injuries to his back, ribs and stomach.

"In a flash, I was face-down on the pavement with multiple officers holding me down, forcing my head into the ground," he said.

"I couldn't see anything, but I could hear my mum nearby, screaming and crying, begging them to let me go.

"That feeling of helplessness will never leave me. The whole experience was embarrassing, deeply upsetting, and exhausting."

In response, the Met said the officers were pursuing a suspected stolen car with false plates before the incident involving Richards, who has accused the force of "racial profiling".

The Met has previously admitted pepper spray had been used during the arrest and said its Directorate of Professional Standards had been informed.

A spokesperson for police watchdog, the IOPC, said its investigation was ongoing.

"The investigation is looking into the use of force by Met Police officers during the arrest of a man, who was later de-arrested," they said.

"In November, we advised an officer that they were under criminal investigation for the potential offence of common assault.

"The same officer is also being investigated for potential gross misconduct and a second officer is being investigated for potential misconduct.

"This does not mean that disciplinary or criminal proceedings will necessarily follow.

"At the end of our investigation, we will decide whether any officers should face disciplinary proceedings and whether any referral should be made to the Crown Prosecution Service."