More traces of explosives have been found on the migrant ship that brought 76 Sri Lankan Tamil men to Canada last month.

The explosive RDX - also known as cyclonite hexogen - is used to make plastic high explosives, mainly for the military.

The explosives residue was discovered in three separate parts of the Princess Easwary, which was intercepted off the coast of Vancouver Island on Oct. 17.

Previously, trace amounts of two other explosives were found on two items of clothing seized when Canadian authorities boarded the ship and took the migrants into custody.

All but one of the 76 men still remain behind bars as border officials attempt to establish the migrants' identities.