Pang Si Da National Park chief Panatchakorn Phobanthit said the arrests were made on Monday following a tip-off .

Panatchakorn said the informant told authorities a large group of Cambodians were felling trees in the Kaeng Dinso, Kaeng Yai and Satone national forest reserves.

Park officials and troops later found around 40 Cambodians walking in line, each carrying a plank of Siamese rosewood on their back to smuggle the precious wood out of the forest. On seeing the authorities approach, they ran into the forest – but nine were apprehended.

Officials seized 75 planks and two chainsaws.

The arrested Cambodians said they sneaked across the border at night and walked four days to the forest reserves. They spent five days processing the planks before starting to walk back when the authorities swooped.