Malaysian authorities have found one corpse as they started digging for bodies at an abandoned jungle camp used by human traffickers on the border with Thailand.

The discovery came as forensics teams began the grim task of exhuming nearly 140 suspected graves in the mountainous area where trafficking syndicates were known to hold migrants for ransom.

Most were believed to be Rohingya Muslims, an ethnic minority fleeing persecution in Myanmar, and Bangladeshis.

Police official Mohammad Bahar Alias told reporters at the site that the exhumed corpse would be sent to a hospital in northern Perlis state for a post mortem.

The camp also contained what police called "human cages" made of wood and barbed wire that were likely used to hold migrants.