President Donald Trump has been forced to pay back $122 million to donors who were tricked into making recurring payments to his 2020 reelection campaign.

A New York Times investigation found Trump's fundraising campaign employed deceptive fundraising tactics that saw thousands of his supporters unwittingly sign up to give repeat contributions, when they had only intended to make a one-off payment.

The 'scam', which involves pre-ticked boxes on fundraising emails often buried under lines of fine print, sparked thousands of complaints to banks and credit card companies.

Among the victims were elderly and military veterans, as well as some experienced political operatives, and many have been left with overdraft fees and busted credit card limits.

Complaints from donors prompted the Trump campaign to eventually reimburse $122 million in contributions.