Police questioned Park Yoo-chun of K-pop group JYJ for eight hours on Thursday evening regarding a series of assault complaints that have been filed against him in the past three weeks.

“I’m sorry to have upset many people. I will comply diligently with police inquiries,” Park told reporters before going in for questioning at Gangnam Police Station on Thursday at around 6:30 p.m.

Police said they questioned Park on whether coercion was involved in his sexual relations with the four complainants in order to establish whether there was sexual assault, among other issues. Police also obtained his DNA sample by mouth swab to compare it with the DNA found in the underwear submitted as evidence by the first complainant on June 10. 

Police say Park will be summoned again for more questioning.

Four women have accused Park of sexual assault, although the first woman subsequently withdrew her complaint. Park has filed a blackmail and libel suit against the first woman. The earliest case dates back to 2014, while the most recent case allegedly took place early June in the bathroom of a bar. All four women were employees at local bars, according to reports.

A 12-member team is investigating Park’s case. Park’s agency C-Jes Entertainment has denied all allegations, announcing Park will retire from the entertainment industry if he is found guilty of any of the charges. Meanwhile, authorities have begun a tax probe into C-Jes Entertainment.

By Rumy Doo (doo@heraldcorp.com)