President Yoon Suk Yeol and first lady Kim Keon Hee arrive at Ninoy Aquino International Airport in Manila, Sunday, to begin a state visit to the Philippines. Yonhap

President Yoon Suk Yeol has denied having close links to Myung Tae-kyun, a key figure involved in first lady Kim Keon Hee's alleged interference with the ruling party's candidate nominations ahead of the April general elections, according to the presidential office, Wednesday.

The office strongly refuted Myung's claim that he has a close relationship with the presidential couple.

"Yoon first met Myung in July 2021 when a senior People Power Party (PPP) official brought Myung to his residence and met him for the second time when a PPP politician visited his residence along with Myung shortly after the encounter," a senior presidential official said on condition of anonymity.

"After spotting Myung at a campaign rally near the end of the presidential primary, a PPP politician advised Yoon to distance himself from Myung. Since then, the president has no recollection of exchanging text messages or talking to him on the phone."

Allegations have surfaced after an online media outlet said that Myung used his relationship with Yoon and the first lady to exert influence in the PPP's candidate nomination process for the April general elections and advise former PPP lawmaker Kim Young-sun to change her district for the elections.

Myung, a self-proclaimed political consultant, claims that he has known Yoon even before he entered politics and has recommended personnel appointments, including Choi Jae-hyung as prime minister. He also argues that he played a substantial role in unifying Yoon, then-presidential candidate of the PPP, and Ahn Cheol-soo, then-presidential candidate of the minor center-right People Party.

Myung also made claims about helping Oh Se-hoon get elected as Seoul mayor in 2021 and assisting Lee Jun-seok to become the leader of the PPP. Both politicians vehemently deny any ties with Myung.

Prosecutors seize evidence from the home of Myung Tae-kyun in Changwon, South Gyeongsang Province, Sept. 30. Yonhap

The scandal is rocking the political arena as prosecutors broaden their investigation.

The Changwon District Prosecutors' Office is investigating whether the former lawmaker Kim had handed over about 60 million won ($44,700) to Myung in exchange for a favor. Prosecutors suspect Myung helped Kim win a parliamentary by-election in Changwon, South Gyeongsang Province, in June 2022.

Separately, the Corruption Investigation Office for High-ranking Officials is looking into whether Myung manipulated poll results to favor Yoon when running a public research company. This comes after a civic group called National Action for Judicial Justice filed a complaint against Myung, the presidential couple and former lawmaker Kim.

The National Assembly's Public Administration and Security Committee had requested Myung to appear as a witness during a parliamentary audit on Thursday, but Myung refused to do so citing the ongoing investigations.

The main opposition Democratic Party of Korea (DPK) blasted Yoon over the snowballing accusations surrounding the first lady and Myung.

"Yesterday, Myung Tae-kyun said in a media interview that 'If I open my mouth, the world will turn upside down.' He warned that if he gets arrested, the regime would not be safe. The public wants to know to what extent Myung and first lady Kim Keon Hee have peddled influence in state affairs. Confess everything before it's too late," Rep. Han Min-soo, spokesperson of the DPK, said Wednesday.

PPP leader Han Dong-hoon acknowledged that public distrust in the government is increasing due to incidents related to Myung, who appears to have acted as a power broker.

"The public will think it is pathetic that many influential politicians appear to be swayed by power brokers. Those who think they are involved in the case should explain themselves," Han said, adding that he believes the first lady should refrain from public activities.

Rising tensions between Yoon and Han have been fueled by differences over the government's medical reform plans and controversies surrounding the first lady, including allegations of stock manipulation, graft involving a luxury handbag and interference in state affairs.