A South Korean lawmaker of the minor progressive party sternly denied a suspicion of conspiracy to commit a rebellion, saying that the allegation was totally fabricated.

"Allegations about me were totally fabricated," Rep. Lee Seok- ki of the left-leaning Unified Progressive Party (UPP) told a press conference Thursday at the National Assembly headquarters.

His comments came a day after investigators of the nation's spy agency and the prosecution raided homes and offices of 10 UPP officials, including Rep. Lee, on charges of conspiracy to stage a rebellion against the state in violation of the National Security Law.

The party officials were charged with a breach of the security law, which bans any activity to prepare, conspires or instigates a rebellion against the state. The law was enacted in 1948 to fight against communism.

The National Intelligence Service (NIS) also put three UPP officials, including the party's vice chairman, under an emergency arrest, while forbidding 14 party officials from leaving the country.

Rep. Lee was not arrested as the detention of an incumbent lawmaker requires parliamentary consent. Lawmakers are immune from arrest in South Korea while the National Assembly is in session.

Investigators from the NIS and the prosecution seized documents and photo files during the raid.

According to tape-recording transcripts secured by the investigative authorities, Rep. Lee allegedly discussed striking major infrastructures and stealing guns from police stations under an emergency situation.

Lee said that the spy agency, which had been a main culprit of the national chaos, was suppressing progressive circles, stressing that it would be an unprecedented suppression.

The NIS has been embroiled in a disgraced incident that the spy agency intervened in politics by tampering with last year's presidential election.

After two months of probe, prosecutors concluded in mid-June that former NIS chief, who headed the agency for around four years under former President Lee Myung-bak, ordered his agents to conduct online smear campaign against opposition presidential candidates.

The prosecution believed that the former spy chief sought to prevent opposition candidates, who he viewed as "leftist followers" of the Democratic People's Republic of Korea (DPRK), from seizing power. The spy agents wrote around 1,900 postings on politics in cyberspace through hundreds of different user IDs.