Britain's public spending chief has urged fraudsters who swindled billions of dollars of Covid support money from the state to give the cash back, Reuters reports.

Chief Secretary to the Treasury Simon Clarke said the tax service, known in Britain as HM Revenue & Customs (HMRC), would pursue anyone who had taken money fraudulently.

"We will now pursue anybody who has taken this money fraudulently," Clarke told LBC radio. "And I would urge anyone who's taken that money and didn't really need it to make contact with HMRC."

"Anyone who thinks that they can escape the long arm of the HMRC is making a great mistake," he said.

The exact amount of Covid fraud is unclear but various estimates put it at around five billion pounds.