Thousands of people have viewed a video on YouTube which shows police officers restraining boxer Adam Salmon, from Morden, as one officer appears to repeatedly punch on him.

The video, filmed in a street in Morden, has resulted in the Met Police launching an investigation by its professional sandards unit

Police say Adam Salmon, 26, of Lynmouth Avenue, who is a boxer and trainer, was being detained after he was seen acting suspiciously on Hatfield Mead before he ran from officers and tried to conceal an item from them.

A police spokesman said: "Following a short foot chase, he was stopped and officers attempted to detain him. As he violently resisted arrest, officers witnessed him attempt to swallow bags of white powder, which following examination, was found to be cocaine.

"He was arrested and taken to a south London police station before being released under investigation. He was charged the following month."

Police released information about the subsequent court case, at Lavender Hill Magistrates' Court on June 15, at which the defendant was found guilty of possession of a cocaine and three counts of resisting/obstructing a police constable in execution of duty.

He was sentenced to six weeks' imprisonment.

The footage of the incident, on May 20 this year, was brought to the attention of the Metropolitan Police on November 5.

A police spokesman said: "The matter was referred to the Directorate of Professional Standards, which deemed it appropriate for a borough level investigation by the local Professional Standards Unit in Merton. Enquiries continue.

The officers shown in the footage have been identified. At this time, there are no restrictions. No complaint has been received from the person who was arrested."

The video has been viewed by more than 2,000 people.