Prostitution is illegal in South Korea, and the charges against Seungri carry a prison sentence of up to three years. "I will cooperate (with the) ongoing investigation and clarify every suspicion", he wrote on Instagram.
Seung-ri has responded on his Instagram account, writing, "At this point, I think it would be best if I retire from the entertainment industry".
South Korean media reported that police had confiscated Seungri's passport now that he was officially regarded as a suspect.
Seungri's agency, YG Entertainment, has yet to release a statement about the issue.
The singer, who also owns a global franchise restaurant business, suspended his entertainment career in February and canceled concerts scheduled for later this month.
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'I have faced heavy criticism from the public for the last month and-a-half and I'm being probed by all investigative authorities in the country, ' Seungri said. "As I've been branded as a 'national traitor, ' I can not stand the fact that I'm harming others for my own sake". Many fans were left shocked after the news surfaced but some had called for him to leave Big Bang as the scandal snowballed.
"I give my heartfelt, honest thanks to fans at home and overseas who gave their love for the past 10 years", he continued.
He then apologized once more.
It is alleged that Seungri tried to obtain prostitutes for clients through a group chat on the messaging app KakaoTalk in 2015.
The scandal comes ahead of the singer's mandatory military service, which all able-bodied South Korean men are required to complete.