Canada's neighbours to the south have apparently been slipping into the country as custom officers let U.S. travellers pass through the border despite the ongoing closure.

Facebook user Pat Chen posted last week about a family from Texas she spotted dining at a restaurant in Banff.

"Today I heard from a friend who posted on her timeline a very disturbing situation happening in Banff and potentially across Canada," she wrote.

"A server in a newly opened restaurant in Banff went to serve a table of four. She asked them where they came from and was stunned to hear that they were from TEXAS! Up for a vacation."

"She questioned them on how they got into Canada when the boarders [sic] are closed to visitors. They replied that they used a loophole. They told boarder [sic] patrol that they were driving to Alaska. They were let in."

"They are now wandering around Banff, no masks, no distancing, no 14 day quarantine. There was also another similar incident same loophole used for another group of visitors from Seattle. Texas has escalating COVID-19 numbers. This is more than alarming!"

Canada Border Services Agency told CTV News that "healthy, non-symptomatic foreign nationals" are allowed to drive through Canada for "non-discretionary purposes," such as travelling to Alaska.

They're being asked to limit stops along the way and use only drive-thrus and pay-at-the-pump when getting gas.

If they do end up having to spend the night at a hotel then they're required to quarantine for 14 days.

Prime Minister Justin Trudeau announced this week that U.S.-Canada border restrictions will be extended again until at least late July for non-essential travel.

Some restrictions have been eased in the meantime, however, like allowing for family reunions.