A massive monitor lizard cooled off in a seafood vendor's fish tub amid the blistering heat in Thailand.

The huge reptile caused chaos when it crawled under the woman's table and took a dip in one of her plastic tubs in Phetchaburi province on April 7.

Footage shows the monitor lizard enjoying a quick soak as the desperate vendor hits it with a sieve to drive it away, with temperatures reaching 40 degrees Celsius.

The beast was eventually chased off into a nearby canal.

Onlooker Anna Chairat said: 'The weather was quite hot. The lizard must have wanted to cool itself off in the water.'

Asian water monitor lizards normally live in canals, swamps, sewers and ponds in cities in Thailand. They feed on fish, snakes, frogs and scraps of food left by humans.

The reptiles are aggressive when threatened and have a mildly venomous bite which sometimes carries harmful bacteria. The Godzilla-like reptiles are also a protected species in the country so their population thrives.