Internal Finance Department documents show officials have deep concerns about the effect of Facebook's planned digital currency on Canada's financial stability.
Officials wrote in the briefing note last summer that they believed the company had yet to address multiple concerns and risks its digital currency posed to the financial system.
The July briefing note, obtained by The Canadian Press under the Access to Information Act, also says the government was working on options to ease the risks.
Officials appeared less concerned about rivals like Bitcoin, which the briefing note says has not played a large role in everyday transactions in Canada for various reasons.
Unlike Bitcoin, Facebook's offering would be a "stablecoin" whose value would be less volatile, and could be easily used by hundreds of millions of the social media giant's users upon release.
The ease of use and stability of value are among the reasons governments and central banks like the Bank of Canada have taken a keen interest in the currency.
