At a bus stop in south London, an off-duty police officer assaulted a youngster who had allegedly robbed two children at knifepoint.

On Tuesday, a passerby captured the cop in civilian clothes putting him in a wrist lock while asking the public for assistance in dialling 999.

A 14-year-old male suspect has been detained in Masons Hill, according to Bromley MPs, “robbery where a phone was stolen and threats of knives were used”.

The officer “bravely interfered” until duty officers came, according to the statement, which also stated that it was aware of the video circulating online.

On Wednesday morning, a Met Police spokesperson confirmed to the Mirror that a suspect has been arrested and that investigations are ongoing.

Last night, author Dr. Shola Mos-Shogbamimu shared the video on Twitter.

She said: “The shock I got while driving to see a man grab a white boy from his neck off his bicycle and struggling forcefully with him- OMG.

“Got out to try to stop it/make sure the boy was OK.

“It was an off duty police officer-he said the boy had a knife & had threatened other kids.”