Police are interrogating an entertainment firm chief suspected of arranging gang rapes of its aspiring singers or habitually harassing them himself.

The investigation is expected to unveil the dirty laundry of showbiz, such as extorting sexual and other favors from young and vulnerable aspiring singers or actors/actresses.

According to the police at Gangnam in southern Seoul, the prosecution on Wednesday has requested a local court to issue an arrest warrant for a 38-year-old trot singer who reportedly harassed and sexually assaulted entertainer-trainees at Open World Entertainment, a medium-sized talent agency.

The investigators have already arrested the firm’s chief, 51-year-old Jang Seok-woo. Two members of a boy band under the firm have been booked without detention for participating in the gang rape. The police suspect the number of victims will top 11, police said.

According to investigators, Jang occasionally ordered trainees to stay late in the evening, until after all the other workers went home, and took them to the basement rehearsal studio. He offered them beer mixed with an aphrodisiac and repeatedly assaulted them, the investigators said.

He also directed the boy band members to sexually assault the victims and watched through surveillance cameras from his office on the fifth floor. The trot singer, signed to another agency, also assaulted and raped the victims several times, investigators explained.

Jang reportedly threatened the victims, who were mostly TV extras or aspiring singers signed with the agency as trainees, saying that if they spoke about the incidents they would not make it in showbiz.

The employees of the firm said that Jang managed to keep his crime so well-concealed that no one in the office was aware of the wrongdoing. They said they have never even seen some of the victims at the office.

The police raided Jang’s office, secured surveillance video and other documents that could corroborate his crimes. They are also expanding their dragnet to whether there are more victims.

Open World Entertainment manages mainly boy bands targeting K-pop fans around the world. Some of its clients are Shinhwa’s Jun Jin, The Boss and X-5, plus actors Ko Joo-won and Shin Ji-soo.

The firm initially denied the report and threatened litigation against media covering the story. But on Wednesday it posted an official apology on its website.

“We are remorseful for what happened. We have let you down,” it said. But the agency denied that some of its singers and actors were involved in the gang rapes. “None of the entertainers in the company has been investigated in the scandal. We hope no one will make groundless rumors about the situation, tarnishing the honor of good people,” it said.

The entertainment firm has halted all official activities for its singers and actors, except for Shinhwa’s world tour, it said.

By Bae Ji-sook (baejisook@heraldcorp.com)