The document leak scandal revolving around former aide Chung Yoon-hoi intensified Thursday as Cheong Wa Dae and a presidential aide accused each other of twisting the truth, while Chung claimed to be the target of a plot.

Chung, a former aide to President Park Geun-hye, denied all allegations during the 16-hour questioning that ended in the early hours of Thursday. Chung allegedly plotted with a number of incumbent presidential aides to influence President Park Geun-hye’s personnel decisions, and other state matters.

During the questioning, Chung is said to have denied the allegations against him and accused Cho Eung-cheon of plotting against him. Cho once served as the chief of Cheong Wa Dae’s office for discipline within the civil service.

According to reports, Chung told the prosecution that Cho drew up false reports to frame three presidential aides including Lee Jae-man, with whom he was experiencing friction.

The allegations, first made official by a news report citing Cheong Wa Dae documents, have set off an expanding investigation and a number of defamation suits. Cheong Wa Dae quickly pointed to police Superintendent Park Gwan-cheon as the source of the information.

With the investigation turning up more allegations, the prosecution is said to be considering bringing the president’s brother Park Ji-man in for questioning.

The president’s brother has often been named in connection with an unofficial group of people pulling the strings behind the Park Geun-hye administration. The younger Park was also rumored to have been engaged in a power struggle against Chung.

In the latest twist, a mid-level presidential aide identified by the surname Oh claimed that Cheong Wa Dae’s internal audit team attempted to force him to single out Cho for planning the leak.

In an interview with a local daily, Oh claimed that Cheong Wa Dae’s audit team repeatedly asked him if Cho was behind everything for seven hours on Dec. 1.

Oh also claimed that the auditors attempted to coerce him to sign a witness account that singled out Cho as the mastermind, but that he refused.

The presidential office, however, claims that Oh had admitted that Cho orchestrated leaking information but simply did not sign the account.

The presidential office also believes that Cho was a key member of the so-called “group of seven” that included Park Gwan-cheon, Oh and a close associate of Park Ji-man.

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