Tourists and vendors inhaled high-inducing nitrous oxide as the Thai government cracked down on the drug's illegal sales.

Footage shows street food sellers casually sucking in the vapour, also known as laughing gas, as they prepared them for sale.

In front of them were baskets of empty balloons which they filled using canisters on the bustling backpacker strip Khao San Road in Bangkok.

Bar girls were seen offering the regulated substance alongside their selection of liquors and cocktails, while signboards announced it was also available at nearby shops.

One visitor said: 'Buying laughing gas is as easy as buying a beer, it's everywhere.'

The gas, commonly used as an anaesthetic in medical procedures, has been used by partygoers to bring on euphoria and hallucinations.

But under local laws, selling the gas without authorisation is punishable by up to five years in prison and a fine of 10,000 baht (235 GBP).

If the source is unregistered, offenders may face an additional three years in jail and a fine of 5,000 baht (117 GBP).

Authorities have warned that misusing nitrous oxide may lead to oxygen deprivation, nerve damage, and other serious health risks.

In June 2024, police raided bars on Khao San Road where they confiscated laughing gas balloons and promotional materials advertising their sale.

Officials said that bars use foreign workers to distance themselves from the illegal activities and avoid prosecution.

In the UK where the substance is also known as 'hippy crack, authorities reclassified it as a Class C drug in 2022 amid concerns about an 'epidemic' of associated health problems and antisocial behavior.

Doctors believe that prolonged use of nitrous oxide can cause serious medical issues, including permanent neurological damage.

Doctor David Nicholl, a consultant neurologist at Queen Elizabeth Hospital in Birmingham, said that youngsters have been left with 'life-changing neurological injuries'.