Jeong entered the Seoul District Prosecutors' Office in southern Seoul at around 9:50 a.m.

"It will be all revealed who pulled this kind of huge fire prank," Jeong told reporters before entering the prosecution office.

It marks the first time for Jeong, who had remained behind the curtain, to appear before the public. 

Asked whether he had a phone call with President Park, Jeong shortly said, "No."

Since launching the investigation, the prosecution office has summoned several people implicated in the scandal for questioning.

Park Kwan-cheon, a senior police officer suspected of drawing up the document, was summoned twice for questioning.

The 48-year-old police superintendent had worked for the presidential office Cheong Wa Dae until early February, when he was transferred to a police station in northern Seoul.

The prosecution also called an informant, who had tipped off Park about the secret meeting, earlier in the day for questioning.

The informant formerly headed a regional tax office and is well acquainted with ranking Cheong Wa Dae officials and secretaries.

Two incumbent police officers, including a lieutenant surnamed Choi, were detained Tuesday for allegedly copying the document, and handing it over to a Hanwha Group employee who eventually allegedly leaked it to the media.

The allegations over his behind-the-scenes intervention in state affairs have emerged as a nation-rocking political scandal, putting the Park administration in the hot seat as it enters its third year in power in late February.

Not much information is known about Jeong apart from that he was a key adviser to the president from 1996-2004. He is also the son-in-law of late pastor Choi Tae-min, who had a close relationship with the president. (Yonhap)