A mystery ‘river monster' turned out to be floating plastic trash caught on a stick in a Thai canal.

The bizarre shark-like figure left residents terrified when they saw it gliding under the dirty water's surface, with some claiming it could be a new species in Bangkok on October 19.

But after three days of confusion, a local confirmed that the would-be scientific discovery was actually made up of tangled garbage.

Footage shows the object being pulled by the current along Samsen Canal. A stick poked out of the water, making it look like a mystery creature.

Local Albert Young said: ‘Most people were convinced it was some type of undiscovered river monster. When I showed it to my girlfriend, she said it was just a stick and plastic.

‘More people also saw through the optical illusion so it's confirmed. It was just garbage.'

However, Albert added it should remind everyone to preserve the rivers.

He said: ‘Someday, a real monster might just come out of the canal, and it's because of the trash we throw onto it.'

Earlier this month, officials in Bangkok increased fines for dumping rubbish in the city's canals as they try to tackle worsening floods across the city.

Waterways in the city are littered with trash and pollution which kills wildlife and prevents rainwater drainage from roads during the annual monsoon season.

Offenders currently receive 2,000 Baht (52 USD) fines, if the law is enforced by police, but that is now rising to 10,000 Baht (262 USD) for members of the public who are caught dump waste into the canals, and if officers enforce the fine.

Bangkok Governor Chadchart Sittipunt said: ' Nine thousand tonnes of garbage are being collected each day, while some of the discarded items end up in canals and clog drainage pipes.

'More boats will be sent to collect waste from waterside residences, there will also be free pickup services on the weekend and bulky items are encouraged to be put at designated areas.'