South Korean President Park Geun-Hye denied allegations that a smear campaign commissioned by the country’s spy agency helped her win last year’s presidential election.

The legitimacy of Park’s election was challenged by the opposition after a probe by the prosecution revealed that the National Intelligence Agency conducted an online smear campaign against opposition candidate Moon Jae-In in the run-up to the December polls.

Woon Sei-Hoon, the former director of the NIS, was indicted for attempting to influence the vote.

“During the presidential election, the NIS gave no help to me and I did not receive any help from the NIS,” Park was quoted as saying by her senior public relations secretary, Lee Jung-hyun, in her first response to the matter.

The chairman of the opposition Democratic Party, Kim Han-gill, sent a letter to Park asking her to accept a National Assembly Investigation into the case, Korea JoongAng Daily reports.

Kim said Park’s silence on the issue worsened the situation. However, Park said she will remain tight-lipped but said would be necessary “to lay bare the truth about the issues raised by the ruling and opposition parties involving the National Intelligence Service.”