The public official ethics division of the Prime Minister’s Office, which placed a civilian under illegal surveillance, may also have gathered information on the chiefs of local conglomerates.

According to reports, the division gathered information regarding conglomerate chiefs ranging from their tax payments to personal meetings in 2008 and 2009, when it is thought to have conducted surveillance on one or more civilians.

“The public official ethics division collected information on conglomerate chiefs ranging from tax payments and inheritance issues to personal meetings,” an anonymous government official was quoted as saying by a local daily.

“The prosecutors’ office, which had confiscated public official ethics division’s computers, is likely to have gained a significant amount of information regarding the matter.”

The investigation into the alleged involvement of Cheong Wa Dae officials in related matters also took a new turn on Friday.

Accusations surfaced that ranking prosecutors prevented former presidential labor affairs aide Choi Jong-seok from being questioned further against objections from working-level investigators.

Choi has been accused by former PMO official Jang Jin-su of ordering him to destroy evidence regarding the matter.

Jang, convicted of destroying evidence, has made a series of claims implicating a number of senior presidential officials in the surveillance scandal and subsequently trying to cover up the incident by ordering the destruction of evidence and by bribing Jang.

The investigators looking into the case are reported to have uncovered that Choi gave Jang a mobile phone registered under a borrowed name to use when carrying out the orders, but they were unable to summon Choi for questioning after higher ranking prosecutors and the presidential secretariat for civil affairs objected.

Instead, Choi was questioned at a hotel in Seoul as a compromise.

The PMO’s ethics division, whose official purpose is to inspect civil servants, was found to have placed a businessman under surveillance for posting negative posts about President Lee Myung-bak.

The case was investigated in 2010 and closed with a number of PMO officials taking the blame. The investigations were reopened recently after Jang made claims that he was acting under the directions of Cheong Wa Dae officials.

By Choi He-suk (cheesuk@heraldcorp.com)