A man was arrested in China after selling an ordinary tree trunk for 1.68 million yuan (S$343,000), reports said.

The man, surnamed Lin, bought the old tree trunk three years ago at 200 yuan, which means he turned a profit of about 8,000 times his cost.

The buyer paid top dollar for the trunk as Lin claimed it came from a phoebe zhennan tree.

The phoebe zhennan is known for glowing with a golden lustre when polished and varnished. Its Chinese name means "golden silk wood".

It was used by Ming dynasty emperors for their thrones and bedroom furniture, and whole logs of the wood were used in the construction of the Forbidden City.

It is now under second-class national protection and sells for a fortune, a report said.

Found in Guizhou, Hubei, Hunan and Sichuan, the tree is listed as a "vulnerable" species by the International Union for the Conservation of Nature.

Lin forged a certificate of authenticity for the tree trunk. The buyer later got an expert to check the tree, and was told that it was worthless. The buyer found that Lin had slipped away by then.

Police later tracked Lin down and arrested him.