A huge petrified log unearthed in Thailand has been declared the world's longest fossilised tree trunk by the Guinness World Records.

The massive piece of wood was discovered in the Ban Tak district of Tak province back in 2003.

It was previously 72.22 metres long, but floods at the excavation site have pared its height down to 69.7 metres, Thailand's Environment and Natural Resources Ministry said. Its diametre was measured to be 1.8 metres.

Environment Ministry Permanent Secretary Jatuphorn Burusphat and other officials received the certificatation from the Guinness World Records during a ceremony in Tak province on July 8.

Jatuphorn said: 'This record will be the pride of Thailand because we have a bountiful environment which has been recognised as world class.

'Additionally, this place could be improved to be a natural tourist site which could make money for the villagers as well.'

He also enjoined the government, the private sector, and Tak villagers to safeguard the environment together.

Somchai Kitcharoenrungroj, Tak provincial governor, added: 'This world record will make Tak province more well-known to the world, and will benefit both our tourist and academic sector.

‘Tak province will develop this area to be a geo park in the future, which would require the cooperation from the villagers who would also directly gain from this.'

Tree trunks can be fossilised when they remain intact are buried below the ground surface by movements of the earth, tectonic subsidence. They are 'petrified' by being turned from wood into stone.