SEOUL • Park Yu Chun, a member of popular K-pop boyband JYJ, has been accused of sexual assault.

Yonhap News Agency said police are investigating after they received a complaint last Friday, alleging that the 30-year-old raped a woman in a bar in Seoul, early in the morning of June 4.

The woman, said to be in her 20s, is identified in reports as a Ms Lee, who works in a nightspot.

In the police report filed by her boyfriend, she claimed that the assault happened in the bathroom of a room where she and Park had been drinking together, reported Yonhap.

She handed over her underwear as evidence. She said she and Park did not know each other before meeting at the bar.

CCTV footage from the bar's hallway did not reveal anything significant, said police, adding that they will summon the two for questioning.

Park's agency C-Jes Entertainment denied the allegations. In a statement, it called the accusation "malicious threats" aimed at damaging a celebrity's reputation. It said it would work with the police to uncover the truth.

Park, 30, started mandatory military service in Seoul in August last year.

He emigrated to the United States as a child, but returned to South Korea after he was talent-scouted. He joined K-pop boyband TVXQ in 2003. Following a contract dispute, he and two other TVXQ members, Kim Jun Su and Kim Jae Joon, formed JYJ.

Park played the lead in the 2012 time-travel romance drama Rooftop Prince. At last year's Paeksang Arts Awards, he won Best New Actor for his role in the movie Haemoo (2014).