Asked if this meant that people who were invited engaged in sexual intercourse, the official said, "Yes," declining to comment any further.

Police said they have questioned a few women as persons of interest in the case and obtained their statements admitting such acts had been committed.

The official refused to give details as to whom the escort services had been arranged for and whether the women hired for the jobs were actually paid.

"We're trying to verify them," the official said.

Police are stepping up their probe into the wide-ranging allegations centering on the 29-year-old, whose real name is Lee Seung-hyun.

Seungri is accused of offering sexual services to prospective investors from abroad at a nightclub in Gangnam in 2015 and arranged a similar event for his own birthday he hosted in the Philippines in December 2017.

He has been under a probe over suspected illegal drug use and sexual violence at Burning Sun, another nightclub in which he allegedly invested cash, and the sharing of sex tapes on a mobile chat with his friends.

Police have been expanding the probe over allegations of collusive ties with the nightclub management and local police.

Police said they have booked a senior police officer, identified only by his last name Yoon, on the charge of violating the anti-graft law, as he received tickets to K-pop concerts from Seungri. (Yonhap)