A security guard at a nightclub on Khao San Road has been charged with assault after a video clip of him slapping and handcuffing a foreigner surfaced on social media.
The management of "The Club Khaosan" nightclub, where the incident occurred, has issued an apology over the matter.
A police complaint was filed against the security guard, who was sacked for a serious breach of the company's regulations.
Pol Col Sanong Saengmanee, the Chana Songkhram police superintendent overseeing the area, said the guard -- identified as Thongchai -- has been detained and charged with assault.
According to police, the incident occurred at about 2am on Saturday when Mr Thongchai was told by a club attendant that a foreign man -- whose identity and nationality were not known -- had stolen a bottle of water.
Sanong: 'Man held, charged'
When confronted by Mr Thongchai, the man admitted he took it from inside the club, believing it was free, police said.
Police said Mr Thongchai said an argument with the foreigner ensued. Following some miscommunication, he became angry and put the foreigner in handcuffs and slapped him twice in the face. Another guard, identified as Krisda, intervened and told the suspect to stop, police said.
A local who was walking past the club took a clip of the incident, which was later posted on social media before going viral, police said.
Mr Thongchai and Mr Krisda were later taken to Chana Songkhram police station for investigation before the guard was charged with assault. Pol Col Sanong said police were looking for the foreign man to get information from him as the damaged party.