We have taken a closer look at the video, and because the suspect is wearing a large Covid mask, it’s impossible to tell if what you’re hearing matches his lip movements. It would be easy to add a fake soundtrack that mentions Helen’s name or another victim.

But for Helen – who had been convinced she was dealing with genuine police officers – the effect was devastating: “After I heard my name like that I was vomiting. It convinced me I was in deep, deep trouble.”

Helen believed Officer Fang when he then told her she would be extradited to China – even though she’s a British citizen.

“He told me: ‘So you got 24 hours, you pack your bags. The police are coming to take you to the airport’.”

Helen was told she could halt her extradition if she could raise bail. After sending over her bank statements for inspection, she was told to transfer £29,000.

“I felt terrible, because I promised my daughter to give her money for her first flat,” Helen says.

But a few days later the fake police were back. Helen was ordered to find another £250,000 or be extradited: “I was fighting for my life – if I go back to China, I may never come back.”

After Helen tried to borrow the money from a friend, he alerted her daughter. Helen broke down and revealed everything. But not before she had put her phone in a kitchen drawer and taken her daughter into a bedroom, and put a duvet over their heads so the scammers couldn’t listen in.

Her daughter listened patiently and explained it was a scam. Helen’s bank eventually refunded her money, but her ordeal could easily have had a bleaker ending: “For two weeks I hardly slept. How can you sleep when somebody is monitoring your phone?”

In her sleep-deprived state, she crashed her car twice. On the second occasion, she wrecked it entirely: “I didn’t kill anyone, but I could have. These types of criminal scam could kill people.”

Other victims of police impersonation scams have been pushed to even greater extremes.

In some extraordinary cases, some Chinese foreign students who can’t meet the financial demands of the fake police have been persuaded to fake their own kidnappings in order to seek a ransom from their families.

Detective Superintendent Joe Doueihi of New South Wales Police fronted a publicity campaign to warn about so-called virtual or cyber-kidnappings, after a series of cases in Australia.

“Victims are coerced into making their own video of them being in a vulnerable position, to appear as if they’ve been kidnapped – tied up with tomato sauce on their body to make it look like they’ve been bleeding, and calling for help from their loved ones,” he says.