KUALA LUMPUR - The fourth suspect arrested over the assassination of North Korean leader Kim Jong-un's half-brother Kim Jong-nam is the first North Korean citizen detained so far and has expertise in chemistry.
Ri Jong-chol, from Pyongyang, graduated in the science and medicine field from a university in North Korea in 2000.
Some 10 years later he was involved in research at a centre in Kolkata, India, until 2011.
Sources said that Jong-chol then returned to Pyongyang before he got an offer from an IT company based in Malaysia.
"It is still too early to conclude that he is behind the liquid poison believed to have been used to kill Jong-nam thus investigation is still underway.
"He is also being quizzed on the whereabouts of three other accomplices, who are still at large," a source said.
Inspector-General of Police Tan Sri Khalid Abu Bakar said the 47-year-old suspect was detained at about 9.50pm on Friday.
"Based on an i-KAD that he has in his possession, the suspect is identified as with date of birth on May 6, 1970, and a citizen of the Democratic People's Republic of North Korea (DPRK)," he said in a statement.
It is learnt that the suspect was arrested after police raided a condominium in Jalan Kuchai Lama at about 11pm on Friday.
On Thursday, Indonesian Siti Aisyah was arrested at a hotel in Ampang at 2am.
Police said she was identified based on CCTV footage at the airport and was alone at the time of arrest.
Her boyfriend was also picked up by police to assist with investigations.
On Wednesday, the first suspect, who holds a Vietnamese passport bearing the name Doan Thi Huong, was arrested at KLIA2 as she was preparing to board a flight to Vietnam.
She had taken a taxi from a hotel in Bandar Baru Salak Tinggi to the airport that day.
Jong-nam, 45, was killed by two women who splashed his face with a chemical at the KLIA2 departure hall at about 9am on Monday. He was about to leave for Macau.
Jong-chol has since been remanded for seven days until Friday.
It is learnt that the suspect often travelled in and out of Malaysia and has been in the country for at least a year.
Police are still hunting for three more suspects, aged between 30 and 50, linked to the case.
In another development, representatives from the North Korean embassy went to the Sepang district police headquarters (IPD) at about 4pm and spent about an hour there.
It is believed that the embassy officials went to the IPD to gain access to Jong-chol.
However, the officials did not stop to speak to journalists waiting outside the IPD.