Prosecutors have raided the office of the anti-corruption team at the Supreme Prosecutors Office, intensifying an investigation into an allegedly illegal ban on a former vice justice minister from leaving the country two years ago.

The Suwon District Prosecutors Office, in charge of the probe, sent prosecutors and police investigators to the team's office in southern Seoul on Tuesday afternoon to secure documents and data compiled when the justice ministry issued an urgent overseas travel ban on the former vice minister.

The team is suspected of having pressed investigators looking into the case to dismiss the suspicions surrounding the ban when it first emerged in 2019.

Kim Hak-ui, who briefly held the vice minister post in 2013, was stopped at Incheon International Airport, west of Seoul, from leaving the country in March 2019 as prosecutors sought to reinvestigate allegations that he received sexual favors from a local constructor more than a decade ago.

He was initially cleared of the charges by prosecutors in 2013 and again in 2015 despite video footage allegedly depicting him in a sexual act.

After the reinvestigation, he was convicted of bribery and sentenced to 2 1/2 years in prison in October 2020 but was acquitted of the sexual favor charge as the statute of limitations had expired.

However, a whistleblower filed a complaint with the state anti-corruption watchdog body in December, saying the ban enforced by the justice ministry did not follow due procedures. Kim was not a criminal suspect in any case at that time and the justice ministry illegally accessed Kim's travel records, he claimed. On Wednesday last week, the whistleblower filed an additional complaint about the anti-corruption team's alleged attempt to dismiss the ongoing probe.

The major opposition People Power Party later disclosed details of the complaints.

The raid followed a spate of recent search operations in other government agencies, including the Incheon airport and the house and office of Lee Kyu-won, the prosecutor who requested the ban at that time.

The ministry denied the accusations against it, saying the issue raised was only "peripheral" and not significant enough to challenge the legitimacy of the decision. There was, it said, an urgent need to ground Kim, who was considered a flight risk, for the public interest.

The anonymous informant who filed the complaint has since sought help from the Anti-corruption and Civil Rights Commission to protect his or her identity, amid growing public and political interest in the case.

The commission said it was reviewing whether to transfer the case to the newly established Corruption Investigation Office for High-ranking Officials.

During a parliamentary confirmation hearing Monday, Justice Minister nominee Park Beom-kye also said it would be better for the new anti-corruption agency to look into the politically controversial investigation. (Yonhap)