Hundreds of empty laughing gas cannisters were left strewn across the Showcase Cinema car park in Walsgrave over the weekend.

Two cleaners out on Monday morning filled black dustbin sacks full of the spent cartridges, which had been used for the consumption of nitrous oxide, also known as ‘hippy crack’.

The trash, also including balloons and empty boxes, is believed to have been left behind by people who have been using the large car park behind the 'de lux' cinema as a meeting place.

Heavy duty speed bumps installed in the space within the Cross Point retail park in Gielgud Way, also outside a Premier Inn, Brewers Fayre and Nando's, haven’t deterred people using it as a meeting place.

The vast haul spanned the entire car park and included clusters of cartridges and spent balloons.

A pile of laughing gas cannisters in the Showcase car park

One local worker, who did not want to named, said: “It’s been happening every Saturday, cars pull up and people use the car park outside the Showcase as a meeting place.

"They have put speed bumps in but it hasn’t made much difference, they are still coming here.

“The police have also been out here but again it hasn’t seemed to have made any difference. It doesn’t give the best impression to the customers using the cinema and the other facilities here.

“We have had travellers in the car park before, but I’m not sure who it was this time.”

Both of the cleaners picking up the trash said they had no idea how such a large number of cannisters could had been scattered across the car park behind the cinema.

Labelling on empty boxes also left behind showed the steel cylinders containing nitrous oxide had been intended for use in whipped cream dispensers.

In product notes on its website, the manufacturer, Best Whip, states:  “We will refuse to sell Nitrous Oxide (N2O) Cream Charger cartridges to you if we suspect you intend to misuse them or are under 18.”

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What is nitrous oxide?

Nitrous oxide was made illegal to supply for recreational use under the Psychoactive Substances Act in 2016.

Known as ‘hippy crack’, the colourless gas induces a quick high when inhaled, usually from a balloon.

According to drug support website Frank, nitrous oxide has several legitimate uses, such as in cooking, in engineering to improve engine performance and in medical procedures as pain relief.

Discarded boxes of Cream Chargers left in the Showcase Cinema car park

When inhaled it can make people feel euphoric and relaxed and even cause hallucinations.

There is said to be a risk of death because inhaling the gas can reduce the amount of oxygen the body can inhale.

However, Professor David Nott, a former drugs adviser to the Home Office, made headlines last month when he said the substance was less harmful than alcoholic drinks such as wine and beer.

Huge hauls of the canisters have been found before. In 2017, scores of the empty cannisters caused concern after being found across suburbs in Coventry.

Showcase Cinemas declined to comment.