Police said the woman they arrested on Wednesday carried a Vietnamese passport and was alone at the time of arrest.
The woman, detained at the low-cost terminal of the Kuala Lumpur International Airport in the Malaysian capital, was identified on the travel document as Doan Thi Huong born on May 31, 1988, police said.
The “suspect was positively identified from the CCTV footage at the airport and was alone at the time of arrest”, they added.
Kim died on Monday after suddenly falling ill at Kuala Lumpur airport. He had been on his way to the Chinese territory of Macau, where he had been living. He was reportedly living under China’s protection.
He died on his way to hospital.
An autopsy will be performed on Wednesday, police said.