COLOMBO, Sri Lanka — Mahinda Kahandagama, the former Colombo municipal politician whose torn red shirt became one of the most recognizable images of Sri Lanka's 2022 political upheaval, was arrested on Monday night on suspicion of possessing crystal methamphetamine, the police said.
Officers from the Colombo Central Crime Investigation Bureau detained Mr. Kahandagama near a restaurant in Mirihana and said they recovered a quantity of the drug, known in Sri Lanka as "Ice," from him. The location has some history. Mirihana is the suburb where crowds gathered outside President Gotabaya Rajapaksa's private residence in March 2022, in one of the first large protests of the movement that later drove the Rajapaksas from power.
The police said preliminary investigations indicated that Mr. Kahandagama had been involved in drug trafficking for some time. A second person, believed to be connected to the alleged operation, was also arrested with a quantity of suspected crystal methamphetamine. The allegations have not been tested in court, and the police said investigations were continuing.
Most Sri Lankans who know Mr. Kahandagama's name learned it on May 9, 2022. That morning, supporters of the Rajapaksa government attacked anti-government demonstrators at GotaGoGama, the protest camp on Galle Face Green in central Colombo, setting off retaliatory violence in the capital and across the country.
Mr. Kahandagama, a longtime supporter of former President Mahinda Rajapaksa, was caught in that backlash. Protesters beat him, tore off his red shirt and forced him through the streets in his underwear. Images and videos of the episode spread quickly and became some of the most widely shared scenes of the day.

His political wardrobe has also changed since then. After the Rajapaksa family lost power, Mr. Kahandagama moved to the camp of Ranil Wickremesinghe, who became president in July 2022, joining the many politicians who found new political homes in the months after the economic collapse.
Four years ago, the crowd was interested in what he was wearing. On Monday, the police were more interested in what he was carrying.