Malaysia's Home Minister Zahid Hamidi says up to 30 mass graves have been discovered near the country's border with Thailand and that he believes more bodies will be discovered.
"We don't know how many there are. We are probably going to find more bodies," Hamidi told Malaysian newspaper The Star.
The graves were found near villages in the state of Perlis in the north of the country. Forensics teams and police commandos are at the scene.
The Star is reporting that as many as 100 bodies were found at one location alone. An unnamed source told Malaysian paper Utusan Malaysia that "hundreds of skeletons" had been found. The victims are thought to be Muslim Rohingya migrants from Myanmar and Bangladesh.
The discovery of the mass graves comes just weeks after the Malaysian government denied there were any human trafficking camps in the country. Now Hamidi admits: "They have been there for quite some time. I suspect the camps have been operating for at least five years."
Asked about the involvement of his countrymen Hamidi said: "Of course I believe that there are Malaysians involved."
So far Malaysian police have declined to comment officially on the gruesome discovery but a press conference has been scheduled for Monday (25 May).
The location of the mass graves is on a well-known smuggling route for traffickers bringing people from Myanmar and Bangladesh to Southeast Asia. Earlier this month a mass grave containing 26 bodies was found across the border in Thailand's Songkhla province, which is near Perlis.
The plight of the minority Muslim Rohingya has provoked an international outcry, with thousands of migrants being stranded at sea in appalling conditions. In one case, around 100 people are said to have died when a fight broke out aboard a boat over food and water.
Last week Malaysian Prime Minister Najib Razak ordered the navy to rescue all migrants still adrift in the sea.