Sadiq Khan has called for police to explain their actions after rapper Wretch 32 shared a video of his 62-year-old father being Tasered at his home in north London.
The footage, shared by the rapper on Twitter, shows Millard Scott tumbling downstairs after an officer is heard to warn: "Police officer with a Taser. Stay where you are.”
As officers ask if he is OK and tell him to keep still, a distressed woman can be heard saying: "They've Tasered him.”
Commenting on the clip, London mayor Khan said an investigation by the police watchdog is now needed.
Khan tweeted: "I have asked the Metropolitan Police for an urgent explanation of this distressing incident which is understandably causing considerable concern.
"It is imperative that the incident is properly investigated by the Independent Office for Police Conduct.
"It is absolutely vital that our police service retains the trust of the communities it serves.”
At the start of the clip, officers can be seen entering the front door of the house as a woman tells them: "I'm not resisting, don't touch me, social distancing, please don't touch me.”
Following the incident, which comes in the wake of protests against police brutality following the death of George Floyd in the US, Scott said he believed he would not have been Tasered if he were white.
He told ITV News: ”I'm lucky to be alive.
"The only people who have invaded our space are the Metropolitan Police. The only people who seem to ignore the guidelines put out there are the Metropolitan Police.
"It seems at this moment in time we are being singled out and targeted.”
Scott’s 35-year-old son, rapper Wretch 32, whose real name is Jermaine Scott, told the broadcaster there has been "no progression" since he grew up watching his father and uncle "fight against police brutality”.
The Met said officers went to the property as part of "a long-running operation to tackle drugs supply linked to serious violence”.
A statement said: "As officers entered the premises, a man came downstairs and started moving towards an officer suddenly.
"He was ordered to remain where he was but continued towards officers who, after several warnings, deployed a Taser.
"The man was not arrested, but was assessed by the London Ambulance Service at the scene. He did not require further medical treatment.
"Officers from the North Area Command Unit have liaised with the family to discuss any concerns they have about the incident.
"The incident, including body worn footage, has been reviewed by the Met's Directorate of Professional Standards and no indication of misconduct has been identified.”
Police said a 22-year-old man found in the house was arrested and charged with encouraging another person to commit an offence under the Serious Crime Act 2007, while a 52-year-old woman was charged with obstructing police after being interviewed under caution at a later date.