KUALA LUMPUR, Malaysia — Malaysian police arrested a second woman Thursday in the death of Kim Jong Nam, the half brother of North Korea’s leader who was reportedly poisoned this week by two female assassins as he waited for a flight in Malaysia.

Police chief Khalid Abu Bakar confirmed the latest arrest to the national Bernama news agency.

Investigators are trying to shed light on a death that set off set off waves of speculation over whether North Korea dispatched a hit squad to kill a man known for his drinking, gambling and complicated family life.

Medical workers completed an autopsy late Wednesday, but it was not clear if or when Malaysia would release the findings publicly.

North Korea had objected to the autopsy and asked for Kim Jong Nam’s body to be returned; Malaysia went ahead with the procedure anyway as the North did not submit a formal protest, said Abdul Samah Mat, a senior Malaysian police official.

Also Wednesday, police arrested the first suspect in the case, a woman carrying Vietnamese travel documents bearing the name Doan Thi Huong. She was picked up at the budget terminal of Kuala Lumpur International Airport, where Kim Jong Nam fell ill Monday. It was not clear whether the woman’s passport was genuine.

She was identified using surveillance video from the airport, police said.

Still photos of the video, confirmed as authentic by police, showed a woman in a skirt and long-sleeved white T-shirt with “LOL” across the front.

Kim Jong Nam, who was 45 or 46, was estranged from his younger brother, North Korean leader Kim Jong Un, and had been living abroad for years.

He reportedly fell out of favor when he was caught trying to enter Japan on a false passport in 2001, saying he wanted to visit Tokyo Disneyland.

According to two senior Malaysian government officials, who spoke on condition of anonymity, the elder Kim died en route to a hospital after falling ill at the airport’s budget terminal.

He told medical workers before he died that he had been attacked with a chemical spray at the airport, the Malaysian officials said. Multiple South Korean media reports said two women believed to be North Korean agents killed him before fleeing in a taxi.

Since taking power in late 2011, Kim Jong Un has executed or purged a number of high-level government officials in what the South Korean government has described as a “reign of terror.” The most spectacular was the 2013 execution of his uncle, Jang Song Thaek, once considered the country’s second-most powerful man, for what the North alleged was treason.

South Korea’s spy agency, the National Intelligence Service, said Wednesday that North Korea had been trying for five years to kill Kim Jong Nam.

The NIS did not say that North Korea was behind the killing, just that it was presumed to be a North Korean operation, according to lawmakers.