In the summer of 2023, a Canadian taxpayer logged into his Canada Revenue Agency account, falsely amended previous tax returns and wrongly claimed he was suddenly owed more than $40 million in refunds.

Then, without verifying the newly filed tax slips, the Canada Revenue Agency authorized the payments and promptly began making the initial instalments, according to sources.

An investigation by CBC's The Fifth Estate and Radio-Canada has learned the scam might never have been detected, except for one thing.

CIBC became alarmed after noticing the government of Canada had deposited an unusually large payment of $10 million to a customer's bank account.

The bank contacted the CRA to make sure it hadn't made a mistake.