Bangkok - A two-metre long shark bit to death a Cambodian crewman while he attempted to untangle a Thai trawler's drag net on deck, media reports said on Sunday.

The Cambodian, a migrant worker identified only as Ham, 21, bled to death after being bitten in the arm and leg by a 200kg shark that had been caught in the trawler's nets 100 nautical miles from shore, said the Bangkok Post.

The trawler's skipper, Chakra Salachua, 37, said Ham was attacked by the shark when he tried to untangle recently hauled up nets on deck.

Conservationists frequently fault Thai fishing trawlers for using drag nets that catch everything from baby fish to endangered species such as dolphins and turtles. - Sapa-dpa