Nancy Pflueger said she doesn’t know who signed the joint federal income tax returns filed for the years 2003 through 2006 for her and her husband, but that the signatures on the documents are not hers.

The wife of retired car dealer James Henry Pflueger testified as a prosecution witness in her husband’s conspiracy and tax fraud trial Wednesday in U.S. District Court.

James Pflueger is accused of failing to report as income money the car dealerships paid to cover his personal expenses and for underreporting capital gains on a $27.5 million sale of an investment property in San Diego.

An IRS auditor testified Wednesday that Pflueger failed to report income of more than $3 million for 2003-2007 and that he owes the federal government, Hawaii and California $1.8 million in taxes.

Nancy Pflueger had opposed the government’s subpoena for her to testify. But U.S. District Judge Leslie E. Kobayashi ruled Tuesday that she does not qualify for the marital privilege that allows people to refuse to testify against their spouses.

Kobayashi said that even though the Pfluegers are legally married, they have been separated for more than 20 years and that James Pflueger has been living with someone else for the majority of that time.

Los Angeles certified public accountant Dennis Lawrence Duban testified last week that Pflueger gives his wife an allowance for her living expenses. He also said Pflueger signed his wife’s name on the tax returns.

Nancy Pflueger said her husband took care of the salary of her longtime gardener and her utility bills.

She said the company that maintains her swimming pool knows to send the bills to the car dealership.

“Jimmy took care of everything,” she said.

The government says the Pflueger car dealerships paid the utility bills, the gardener’s salary and health insurance and for the health insurance for James Pflueger’s wife, daughters and his companion, who Duban and defense lawyers described as Pflueger’s significant other.