The money that the Internal Revenue Service sent last month to Abigail Roberts, 61, who works in Widener University's cafeteria, came from funds the real princess had on deposit with the IRS, according to court documents.
Federal authorities say Roberts fooled the IRS by using the social security number of the genuine heiress, Abigail Kinoiki Kekaulike Kawananakoa, on her tax form.
Kawananakoa, 73, is heir to the Campbell estate, one of the largest landowners in Hawaii.
"They're saying I'm not who I say I am," said Roberts, who was born in Hawaii as Charlotte Veronica Kuheana and lives with her husband in the Philadelphia suburb of Chester.
"I am the last heir. The only regret that I have is that no one believes I am telling the truth," she said.
The IRS used warrants to get most of the tax refund back earlier this month from the bank where the couple deposited it. The agency is suing Roberts and her husband to recover more than $100,000 that apparently was spent.
Authorities said it is not the first time Roberts has collected from the IRS that way. In 2001, she was acquitted of alleged tax-refund fraud for more than $34,000 she received in 1994 from a trust set up by Hawaiian royalty.
Her attorneys claimed she was suffering from an "irrational insistence upon an identity that is not her own."
A federal judge ruled in that case there wasn't enough evidence to show Roberts had an intent to commit a crime but warned her that she had no legal right to proceeds of the estate, according to court documents.