Authorities say the people behind a series of scam emails and phone calls claiming to be from the Canada Revenue Agency are taking a new approach by contacting previous victims again.

According to the RCMP, there have been a number of reports of emails being sent by people who had previously turned over cash to scammers.

The emails claim that the money lost can be refunded if the recipient agrees to first pay about 5 per cent of the amount as a so-called administrative payment.

RCMP say that they are still receiving far fewer reports of CRA scams than they were before October, when 70 people were arrested in India as part of their investigation into call centres allegedly behind scam phone calls.

Since 2014, more than 2,000 Canadians have reported paying more than $6.2 million to fraudsters pretending to be Canadian government officials – although the RCMP believe the real numbers may be much higher.

One of the most obvious signs of a potential scam, authorities say, is a request for money to be transferred through pre-paid credit or gift cards, Western Union or similar services, or electronic transfers.