Key workers who are returning to the NHS to help it cope during the coronavirus pandemic are being targeted by promoters of tax avoidance schemes, a Money Box investigation has found.

Adverts posted on social media are designed to push key workers towards umbrella companies operating on the fringes of the law which, alongside standard ones, act as employers for freelance contractors.

Posing as a health care worker, our reporter was told how she could legally hide a large chunk of salary from the taxman saving thousands of pounds.

Her Majesty's Revenue and Customs (HMRC) is warning people not to sign up to what it describes as these "unscrupulous companies", saying some people could end up with large, unexpected tax bills.

Presenter: Paul Lewis