Video report by ITV News Correspondent Richard Pallot
There have been almost 4,500 whistleblower complaints to Her Majesty's Revenue and Customs (HMRC) as businesses force furloughed staff to work, ITV News can reveal.
HMRC have informed ITV News of how unscrupulous employers are scamming taxpayers into working while also claiming cash from the government's Job Retention Scheme (JRS), also known as the furlough scheme.
Two whistleblowers who wish remain anonymous told their stories to ITV News Correspondent Richard Pallot.
A IT worker in his 40s, who works for a small company in London, has described his employers as being "plain criminals" for making him work despite being on the furlough scheme.
I was very happy for a long time in this firm, but one day, they said to me that they needed to save money in difficult times and that they wanted to furlough me but keep on working - I said that's not allowed.
"They said just do it and don't tell anyone," he added.
When asked by ITV News Correspondent Richard Pallot whether his company knew it was illegal, he said: "Absolutely."
I sent them repeated emails with the government rules, saying it was fraud - they didn't care. They then fired me.
The former IT worker also said there are still "dozens of employees" working at the company despite being furloughed.
ITV News also heard from a receptionist who was furloughed in March and says she hasn't received a single penny.
However she discovered last week the government had paid her wages from April onwards - but her bosses had kept it to themselves.
She told ITV News: "Well it's horrible - you're put in a situation where you feel helpless and you've got no one to turn to and her and her business partner are living off everyone else's money."
ITV News has been contacted by dozens of people with similar complaints. One manager of a beauty company said: "It is completely unfair. I am furloughed but forced to work three days every week."
"I was told if I don't work they will cut my pay even more," she added. A recruitment consultant also told ITV News: "I was pressured into working and I was told if I missed my sales target my job would be in danger."
She added: "When I raised this as unethical my boss dismissed my concerns and said there was nothing to worry about." And a restaurant waiter told ITV News: "We are working harder than before lockdown, but we need our jobs."
But Whistleblowers UK said large numbers of workers are still not coming forward.
Georgina Halford-Hall, Chief Executive of Whistleblowers UK, told ITV News: "We have been confidentially told that the true level of this problem is really unknown and it's probably far an excess of the numbers that have been reported so far."
"Not least because of the failure by HMRC to implement a furlough fraud reporting hotline from the beginning" of the pandemic, she added.
UK’s whistleblower charity, Protect, said their advice line has seen record numbers of calls related to furlough fraud.
Protect’s Chief Executive Elizabeth Gardiner said it’s the single biggest issue Protect has dealt with in its 27 year history.