Hong Sa-duk, a key aide to the ruling Saenuri Party’s presidential candidate Rep. Park Geun-hye, quit the party Tuesday after he was accused of taking illegal political donations.

“I voluntarily leave the party so as not to burden the party and its candidate,” the former lawmaker said in a statement. Hong, regarded as Park’s right-hand man, headed the presidential hopeful’s campaign team during the party’s presidential primary.

The National Election Commission on Monday filed a complaint asking the prosecution to investigate allegations that Hong received some 55 million won ($49,000) from a businessman in South Gyeongsang Province.

Both denied the allegation, which was first raised by the businessman’s former driver. The business executive said his former employee had demanded money, threatening to divulge the alleged bribery.

Hong said the charges were politically motivated, coming just three months before the presidential election.

“I am in no simple position within Park’s camp and it is regrettable that these allegations are being raised at such a critical point in time,” he said.

“The local prosecutors already looked into the case and confirmed that my bank accounts were clear.”

He also demanded that the prosecution wind up its investigation as soon as possible, pledging to suspend all political activities until he is proven innocent.

Hong denied any influence by Rep. Park or the party leadership in his decision to leave the party. But his swift defection was largely regarded as the party’s attempt to contain the fallout from the scandal.

Despite her pledge to eradicate all political irregularities, Park has been hit by bribery allegations involving former lawmaker Hyun Ki-hwan and proportional representative Hyun Young-hee.

The party’s former public communications official Jeong June-guil was recently accused of making threatening calls to professor Ahn Cheol-soo’s aide to stop Ahn from joining the presidential race.

The main opposition Democratic United Party denounced Hong’s defection as an attempt by the right-wing party to shield its candidate from the scandal.

“The Saenuri Party is no more than Rep. Park’s private political clique. Its top priority is to protect Rep. Park,” said DUP spokesperson Rep. Jung Sung-ho.

The DUP demanded Park apologize and take responsible measures for irregularities surrounding her aides and party members.

By Bae Hyun-jung (tellme@heraldcorp.com)