A Canberra man has been imprisoned by immigration officials in the United States for overstaying his US visa by less than two hours, after being denied entry to Canada.

Baxter Reid, 26, and his American girlfriend, Heather Kancso, travelled to the Canadian border in upstate New York before Mr Reid was arrested by US border police on Monday, April 24 local time.

Mr Reid is now imprisoned at Buffalo Federal Detention Centre where he could face six months in jail before his case is heard by a judge.

Ms Kancso has started a GoFundMe campaign to raise money for Mr Reid's legal costs.