Contestants on Netflix’s Squid Game-inspired reality show have slapped the production company with a lawsuit over injuries suffering during filming.

Squid Game: The Challenge was shot in London back in January – parts of it in a cold snap, with temperatures plunging as low as -3 degrees.

On Thursday (British time), lawyer Daniel Slade said letters of claim had been sent on behalf of contestants who allege they suffered injuries such as hypothermia and nerve damage “as a result of poor health and safety standards on set”.

“From what we’ve been told, they pushed the boundaries of safety in the name of entertainment,” Slade said.

“Production companies need to ensure that health and safety standards on their shows don’t leave people at risk of harm.”

In all, 456 people entered the Squid Game reality competition, which was inspired by the runaway success of the South Korean drama series. But, unlike the original, the stakes weren’t life and death.

Contestants came from all over the world, including three from Australia. They were competing for a cash prize of £3.6 million ($A6.95 million), the largest prize Netflix has offered in reality television.

“Through a series of games, each player will be pushed to their limits and forced to ask themselves just how far they’ll go to win, with opportunistic alliances, cutthroat strategies and ugly betrayals to follow,” Tudum by Netflix said.

The legal action follows reports earlier this year that up to five contestants suffered frostbite and minor injuries as the first episode – titled ‘Red Light, Green Light’ – was filmed in a cold snap.

“It was like a war zone. People were getting carried out by medics, but we couldn’t say anything. If you talk then you’re out,” sources told Britain’s Sun newspaper in January.

Slade told The Sun this week that contestants thought they would be “taking part in something fun”, and those who walked away with injuries didn’t think they would “suffer” like they did.

“They have been left with injuries after spending time being stuck in painful stress positions in cold temperatures,” he said.

“One client describes seeing someone faint, then people shouting for medics. We have a case where someone complains of hypothermia. One had his hands turn purple from the cold. Such injuries can have very serious long-term health implications. One of our clients complains of being given ill-fitting clothing, despite the cold conditions.”

Netflix responds to lawsuit

Last week, as claims of injuries began to emerge, one of The Challenge‘s producers, John Hay, said safety was “paramount”.

He told The Hollywood Reporter appropriate measures were taken to look after contestants, and filming of ‘Red Light, Green Light’ had been “complicated”.

Hay said it was a cold day and the shoot was long. But he said everyone involved was prepared and had been looked after properly.

Executive producer Stephen Lambert also defended the show – because it was giving out a huge cash prize.

“We’re giving away the largest prize in TV competition history. It wasn’t going to be a walk in the park to win [millions],” he said.

Lambert acknowledged “tough” moments on set but said it was “a lot easier than an awful lot of unscripted shows” – especially compared to survival-style reality series.

“This is no harder than those, and in lots of shows you have people sometimes treated for mild complaints, which is what happened in that particular game,” he said.

Back in January, Netflix denied reports anyone was seriously injured on The Challenge set. It said it cared deeply about the health and safety of cast and crew.

“[We] … invested in all the appropriate safety procedures,” the streaming service said.

“While it was very cold on set – and participants were prepared for that – any claims of serious injury are untrue.”

Episodes of Squid Game: The Challenge are being released weekly. The next is due on November 29.