Sally Ann Johnson, 41, was paid the massive sum over several years by an elderly woman who believed that she was possessed by demons.

But US District Judge Denis Casper in Boston said the evidence suggested that the elderly woman was suffering from dementia and Ms Johnson had taken advantage of her by claiming to be able to help.

Ms Johnson has been ordered to repay the woman the nearly $3.57 million she received between 2007–14 and to pay $725,912 in restitution to the US government for the taxes she avoided.

She was then jailed for 26 months.