A driver using nitrous oxide canisters while on a motorway was caught by police.

Officers stopped the vehicle last night on the M25 near Swanley after all the occupants were seen using the recreational drug.

The driver was subjected to tests and two cardboard boxes of canisters were seized.

Police have been asked for further information about what happened.

Nitrous oxide, or laughing gas as it is also known, is one of the most commonly used drugs among 16 to 24-year-olds.

The canisters are made for medical and commercial use – such as to make whipped cream in catering – but it is illegal to be sold as a drug.

Side effects for heavy users can include dizziness and impaired memory, while inhaling directly from the large canisters can be fatal.

The government is proposing to ban the sale of the canisters as part of a drive to clamp down on anti-social behaviour and the Home Office has asked for a report into the harm caused.

The supply of the gas for inhalation is banned but tighter restrictions could soon be put on all direct consumer sales.

Litter-pickers in Greenhithe welcomed the government's suggestions earlier this month after they continually find small silver pellets and, more recently, larger canisters dumped around the town.

In 2020, Labour MP for Canterbury and Whitstable, Rosie Duffield, called for "fast action" to be taken against laughing gas as she called for tighter regulations around its sale.

She suggested raising the age limit to over 25.