The chief of a Seoul district prosecution office offered to resign Friday over a sex sandal involving a junior prosecutor, the latest in a series of incidents which have tarnished the elite law enforcement agency.

The Supreme Prosecutors’ Office launched an investigation into allegations that a trainee prosecutor performed sexual acts with a female suspect in his office during an interrogation after promising to clear her of charges.

The incident comes as the prosecution office falls under growing criticism after prosecutors were ensnared in a series of incidents involving bribery, sexual harassment and verbal abuse of police officers.

“We are conducting an inspection into the law school graduate who is currently working as a trainee prosecutor at the Seoul Eastern District Prosecutors‘ Office,” said Lee Jun-ho, chief of the inspection team Thursday.

Seok Dong-hyeon, chief of the Seoul Eastern District Prosecutors’ Office, said Friday that he will step down from his post to take responsibility.

The accused prosecutor, 30, whose name is withheld, was interrogating the 43-year-old woman without the presence of an inspector, which is against the law.

The prosecutor also had sex with the woman at a nearby motel several days later, the inspectors said.

The misconduct was revealed when the woman tipped off her lawyer, who then asked the prosecutor in charge of supervising him.

“The two involved in the incident made a written agreement not to mention their inappropriate acts to anyone,” said the lawyer.

The trainee prosecutor was interrogating the woman on a Saturday because she said that was the only day she had available. According to a prosecution source, the acts happened by accident when he was placating her.

The official also said the woman called the trainee several days later and they went to the motel together. She allegedly asked the trainee for 50 million won ($46,000) for a settlement.

The inspection team plans to call in the prosecutor to question if he forcefully requested the sexual relations in exchange for favors.

The sex scandal came after chief prosecutor Kim Kwang-jun who received around 900 million won from conman Cho Hee-pal and Eugene Group, a construction-based conglomerate, was arrested last week.

Other prosecutors reportedly involved are being investigated by a special counsel team.

Prosecutor-General Han Sang-dae apologized Thursday for the strings of immoral acts of his employees who are supposed to represent justice and protect the public.

He convened a meeting on the same day with the heads of prosecutors’ offices nationwide and discussed how to strengthen the self inspection and achieve the reform.

The announcement for prosecutorial reform is expected to be unveiled before Dec. 7, earlier than previously thought, due to the latest sex scandal.

However, the public cast doubt on the authority’s promise for reform which has been pledged every time such scandals happened. Previous incidents include the “Benz prosecutor” case in 2011 in which a prosecutor was bribed with a Mercedec-Benz and a brand-name purse; the “sponsored prosecutors” in 2010 in which a dozen prosecutors received sexual favors from a construction firm; and the “Grandeur prosecutor” who received a car and money in return for favors to a suspect in 2008.

By Kim Young-won (wone0102@heraldcorp.com)