Malaysian police said on Wednesday that a woman was arrested as part of the investigation into the death of a man from the Democratic People's Republic of Korea.

The police said the middle-aged man, who died on Monday at Kuala Lumpur International Airport, was holding a passport under the name Kim Chol.

Khalid Abu Bakar, chief of the Malaysian police, said 46-year-old Kim, who was born in Pyongyang, sought medical assistance at the customer service counter of Kuala Lumpur International Airport 2 before he died en route to a hospital.

The investigation is in progress and a postmortem examination request has been made, the police said.

Geng Shuang, Foreign Ministry spokesman, said on Wednesday that China has noted the media reports and was closely following the development of the case.

While police are identifying the man on the basis of his travel documents, news media from the Republic of Korea have reported the man was Kim Jong-nam, the elder half-brother of the DPRK's top leader Kim Jong-un.