Human rights group Amnesty International is calling on Thai authorities to investigate allegations police tortured a pair of suspects who reportedly confessed to killing two British tourists last month.

The tourists were found dead on Koh Tao island, and police last week arrested two migrant workers from neighboring Myanmar who they said had admitted responsibility for the killings.

Police deny the suspects were tortured, and say they have DNA evidence backing up the confessions.

Amnesty cited a lawyer from the Myanmar Embassy's legal team as saying that one of the migrants "alleged police beat and threatened him with electrocution."

The group said "numerous sources" have also reported "acts of torture and other cruel, inhuman and degrading treatment" of other migrant workers in connection with the investigation.