A lawyer acting for Diana Ross says the singer has evidence she served the correct jail time, following a judge's decision to send her back to prison.
Diana Ross pleaded no contest to a drink drive charge
The judge disputes whether Ross spent 24 consecutive hours in jail, as she served 48 hours for drink-driving.
"I think we actually have proof from her. She documented it in her diary," said Ross' lawyer Jim Nesci.
Ross has been ordered to return to court in Arizona on 1 April for a decision to be made on her sentence.
The 59-year-old singer was arrested in December 2002 after she was seen driving the wrong way on a road in Tucson, Arizona.
She was found to be two times over the legal drink drive limit, and pleaded no contest to a drink driving charge.
Ross arranged to serve her 48-hour sentence in Greenwich, Connecticut, where she
lives. Her sentence also included at least 36 hours of alcohol abuse treatment.
But Tucson City Court magistrate T Jay Cranshaw found that Ross failed to serve 24 consecutive hours as required by Arizona law.
The singer served 47 hours in the custody of Greenwich police over a three-day span, Cranshaw found.
On her last stay at the Greenwich prison, police records show that Ross arrived at 8am on 11 February and stayed for 22 hours until 6am the following day.
"To avoid questions of impropriety, the defendant is ordered to return to Tucson to serve 48 consecutive hours in the Pima County Jail," Mr Cranshaw stated in a written order.