South Korean president Park Geun-hye is facing a political crisis amid allegations a former aide influenced important state decisions.
Chung Yoon-hoe is alleged to have regularly met senior Park aides, and it is claimed he was involved in the decision to dismiss staff from the cultural ministry.
He is also alleged to have feuded with Ms Park’s younger brother, Park Ji-man. Mr Park, who appeared before prosecutors on Monday for questioning, denied allegations that he tried to influence national affairs.
The scandal, which has affected Ms Park’s approval ratings and led to political gridlock, has gained momentum in recent days after local newspaper Segye Ilbo reported the allegations, based on leaked internal documents from the presidential Blue House.
Mr Chung told reporters he had not been in touch with Ms Park’s associates for years. Some of the president’s secretaries were also questioned by prosecutors over allegations they were involved in a power struggle with the president’s brother. They have denied the allegations.
Mr Chung, who was Ms Park’s chief adviser while she was a lawmaker but before she became president, was questioned by prosecutors last week.
The scandal has dealt a blow to the president’s reputation. As South Koreans raise questions over Ms Park’s opaque style of leadership, her approval ratings have fallen to their lowest level since taking office in February 2013.
The controversy deepened after a police officer suspected of leaking the documents was found dead on Saturday in an apparent suicide. The officer left a note proclaiming his innocence.
Ms Park has dismissed the allegations as groundless, saying Mr Chung had not worked for her for many years. The president added that she had ordered a thorough investigation into how the internal documents were leaked.
The scandal has stoked criticism that the president shares the authoritarian leadership style of her father, Park Chung-hee. Park, the military dictator, oversaw South Korea’s rapid economic development between 1961 and 1979 but has been accused of suppressing political dissenters.
The allegations have sparked a political stand-off between the ruling New Frontier Party and the opposition New Politics Alliance for Democracy, which is calling for an overhaul of the presidential administration. Partisan gridlock has prevented legislation being passed in parliament.
“Even if the allegations are not true, they are gaining weight as people are not pleased with the perceived lack of transparency in the way the president handles national affairs,” said Lee Joon-han, a political professor at Incheon National University.