The man was detained in what the force described as “an area well known for drug dealing” in Croydon on Wednesday.
Footage shared on TikTok, which has been viewed more than 400,000 times, shows one officer saying to the man “you’re not dressed for the climate”.
Another officer added the man’s outfit “just seems odd”.
A statement from the Met said the man was “wearing several layers of clothing despite the warm weather” and that he “became hostile and refused to account for what he was doing” after being approached by officers.
He was detained and searched under the Misuse of Drugs Act and he “went on his way” when nothing was found.
Det Ch Supt Lee Hill said the force was aware of the footage, adding: “This shows only a small part of this incident and we would ask people not to rush to judgement.
“In this instance, a formal complaint has been received and is being handled in accordance with the Police Reform Act. This will include a review of all the available footage, including the officer’s body-worn video.
“Our officers have to conduct themselves in the most challenging of circumstances and it is right their actions should be subject to public scrutiny”.
