A third person has been arrested in connection with the “assassination” of the North Korean leader’s half-brother Kim Jong-nam, Malaysian police have said.

The suspect was reportedly detained on Thursday morning and is believed to be the boyfriend of one of the two women already arrested. Police said he provided information that led to the arrest of a woman who was using Indonesian travel documents.

The latest arrest follows the detention of two female suspects who were arrested separately on Wednesday and Thursday, one of whom held a Vietnamese passport and the other an Indonesian passport, although there was no immediate way to determine whether the IDs were genuine.

The women were identified using CCTV footage from Kuala Lumpur airport, where they are suspected to have sprayed a poisonous liquid into the face of Mr Kim on Monday as he prepared to board a flight to Macau, causing him to suffer a “mild” seizure and die shortly afterwards.

Still photos of the CCTV video, which circulated widely across the internet on Wednesday, showed the woman in a skirt and long-sleeved white T-shirt with “LOL” — an acronym for “laughing out loud” emblazoned across the front.