Police have sought a warrant to detain the son of Rep. Chang Je-won of the main opposition People Power Party(PPP), who is suspected of assaulting a police officer seeking to test him for drunk driving.

The Seocho Police Station in Seoul said on Friday it filed the request for Chang Yong-joon, a rapper whose stage name is “NO:EL", on charges of violation of the road traffic act, injuring and obstruction of duty. 

The 21-year-old drove a Mercedes-Benz into another vehicle near St. Mary Hospital in southern Seoul on September 18. He refused to take a sobriety test and head-butted the police officer instead. He was questioned on the matter for around six hours on Thursday. 

The road traffic violation charge applied covers refusing to take an alcohol breath test, driving without a license and property damage, but excludes the charge of drunk driving. 

Chang was booked on a separate charge in April for assaulting a pedestrian in Busan. He was also sentenced to a suspended jail term for drunk driving last year.