The Mexico City prosecutors' office says five police officers have been arrested in connection with a video that appears to show the abuse of a suspect.
Milenio Television reported last month that one of its reporters had taken the video of an officer repeatedly pushing the man's head into a bucket of water while his T-shirt was pulled up over his head and face.
The alleged abuse took place following a shootout between police and gunmen in the working-class neighborhood of Tepito. The video's authenticity could not be independently confirmed, and neither Milenio nor police released the suspect's identity.
The Mexico City prosecutor's office said in a statement that five officers had been placed under house arrest for 30 days while it seeks preliminary charges of torture.