A man has been arrested in connection with an alleged fraud that involved callers posing as Canada Revenue Agency (CRA) officials and demanding payments for back taxes, the Toronto Police Service announced on Tuesday.

Police arrested Abhi Thakkar, 20, on Jan. 25 and charged him with one count of fraud over $5,000, three counts of fraud under $5,000, four counts of possession of property obtained by crime, and one count of money laundering.

The allegations have not been proven.

According to Toronto police, a group made unsolicited phone calls to random people, purporting to be from the CRA. The targets of these calls “were told they were in arrears of their income tax, and were threatened with imprisonment if payment was not made immediately,” Toronto police say in a statement. Police are aware of victims in Ontario and Alberta, and believe there may be other victims across Canada.

Police are also warning the public about these sorts of scams once again. “Never send money as a result of an unsolicited phone call without first independently verifying the legitimacy of the request,” the Toronto police statement says. “End the call and contact other trusted family, relatives, or friends to verify the information you are being told.”

Warnings about scams that involve unsolicited calls or emails from people posing as tax or regulatory officials, and demanding payments from victims, have repeatedly been issued by police, tax authorities, and securities regulators in recent years.

See: CRA warns taxpayers of fraudulent communications