A beachgoer was put in a chokehold on the famous Copacabana strip for not wearing a face mask.
The Brazilian police officers were caught on camera grabbing him round the neck then firing a taser at him in front of screaming onlookers.
The incident occurred on the iconic beach in the city of Rio de Janeiro.
The authorities said the unit found the unnamed man, who appears to be wearing a face mask in the video, without a mask when they saw him.
He was accompanied by three women at the time.
The Municipal Guard said the 25-year-old man refused to put the mask on or identify himself to the agents, local media outlet Globo reported.
In the video, the officers can be seen surrounding the man who tells them to "get off" him.
One of the officers grabs the man by the neck, and he shouts "let go of my neck, let go of my neck".
The officer can be seen putting the man in a chokehold but he manages to wriggle free and then throws the officers to the ground as onlookers scream in chaotic scenes.
One of the officers then fires at the man with a taser, with two shots heard as the man screams in pain on the sand.
A woman comes running and the man recording tells her to keep her distance.
The officers can be seen putting the man in handcuffs and lifting him to his feet before putting his face mask over his nose and mouth.
Local media outlet UOL reports that the man was taken to a local police station and charged with contempt, disobedience and resisting arrest.
In Rio, beachgoers must wear a face mask and are allowed to play collective sports from Monday to Friday, with only individual sports allowed at the weekends.
Beachgoers cannot sunbathe.
According to the latest figures from the Johns Hopkins University, Brazil has registered 2,098,389 cases of Covid-19 with 79,488 deaths, second only to the United States.
