The pair were detained after they crossed a “security line and aggressively tried to approach the prime minister” who was visiting a mosque in Kuching on Borneo island, according to a police statement.
“Both of them were subsequently arrested for failing to comply with police instructions not to cross the security line,” it said.
The journalists work for the Australian Broadcasting Corporation’s Four Corners investigative programme.
“ABC 4Corners team arrested in Malaysia last night after trying to question PM Najib Razak over corruption scandal,” the programme’s executive producer Sally Neighbour tweeted Sunday.
Reporter Linton Besser and camera operator Louie Eroglu had approached Najib on the street before their arrest, the broadcaster added.