Two former chiefs of South Korea's National Intelligence Service were arrested on Friday over illegal transfers of money to the secretaries of impeached South Korean President Park Geun-hye, local media reported.

Axar.az reports citing Sputnik that, the Seoul Central District Court approved the arrest of Nam Jae-joon and Lee Byung-kee amid fears that they may escape or destroy evidence, the Yonhap news agency reported.

The two men are accused of transferring money to impeached South Korean President Park's senior secretaries Ahn Bong-geun and Lee Jae-man, with Nam initially paying 50 million won ($45,536) every month and Lee increasing the amount to 100 million won. The money was allegedly used for illegal political activities, including an election poll for the conservative bloc.

NIS has recently faced severe criticism over its involvement in South Korea's politics. In August, it was revealed that the agency had conducted online smear campaign against former President Roh Moo-hyun (2003-2008) to manipulate public opinion in favor of Lee Myung-bak, nominated for the 2008 presidential election by South Korean conservatives.

The agency was also accused of interfering in the 2012 presidential election, when Park, nominated by conservative Liberty Korea party, won over then-Democratic Party's nominee Moon Jae-in.

Reforming the NIS was one of Moon's election promises. In June, new NIS Director Suh Hoon banned domestic intelligence operations from gathering information on ministries, media and other organizations and established a reform committee, which was tasked with regaining public trust by transforming the NIS into a credible agency.