A U.N. envoy, who is visiting South Korea to investigate violations of freedom of expression, complained to the South Korean government that he was being followed, the local Hankyoreh newspaper said.
The government denied any knowledge, it said.
Frank La Rue, the United Nations Special Rapporteur for Freedom of Opinion and Expression, who is currently visiting South Korea for research, complained to the Foreign Ministry that he believed he was being followed, the newspaper said on Saturday in an editorial.
The newspaper called for the National Intelligence Service (NIS), the nation's main spy agency, to clarify on the allegations, in an apparent indication that the act was done by the spy agency.
La Rue reportedly mentioned his suspicions during a May 6 meeting with Deputy Foreign Minister Chun Young-woo, presenting as evidence a photograph of a car with someone inside filming his activities with a camcorder, it said.
Hankyoreh also cited the Voice of the People, an Internet-based newspaper in South Korea, reporting two days ago that it had confirmed through an NIS official that the car at the scene was an NIS vehicle.
The NIS, however, denied that the vehicle in question is affiliated with the service, and police also said that the incident had nothing to do with them, the newspaper said.
La Rue is on a mission to assess the level of freedom of expression in South Korea and stays here May 17.
The newspaper claimed that the Lee Myung-bak administration has a "disagreeable attitude" regarding La Rue's South Korea visit and the envoy's request to meet with government officials, including public prosecutor general, and commissioners of the National Human Rights Commission and NIS, didn't take place.
Prior to his arrival, foreign ministry spokesman Kim Young-sun said in a press briefing: "South Korea has a pretty advanced level of freedom of speech."