Updated

A Florida appeals court on Tuesday denied a request that would have stopped Casey Anthony from being forced to start a one-year probation sentence for check fraud by the end of the week.

The Fifth District Court of Appeals disagreed with Anthony's argument that enforcing the probation order would violate the constitutional prohibition on double jeopardy. Anthony maintains she already had completed the probation sentence in jail while she was awaiting trial on murder charges in the 2008 death of her 2-year-old daughter, Caylee. The ruling upheld a lower court's order requiring Anthony to report to a Florida probation office no later than noon Friday.

"The petitioner and her attorneys were well aware that her probationary placement was not to begin until her release from confinement," the appellate court said.

A Florida jury last month acquitted Casey Anthony of murder in the death of Caylee, in a case unrelated to the check fraud. After her release, the 25-year-old vanished from public view amid threats against her and she has since kept a low profile. However, her attorney says she is back in Florida.

The probation order stems from a sentence Circuit Judge Stan Strickland imposed in January 2010 after Anthony pleaded guilty to stealing checks from a friend. At the time, Strickland said Anthony should serve the probation upon her release, but those instructions never made it into a written order. Corrections officials interpreted the sentence to mean Anthony could serve the probation while she was in jail.

In an order this month, Strickland clarified that Anthony must begin her probation now that she is out of jail. He then recused himself from the case and turned it over to Judge Belvin Perry, who presided over Anthony's murder trial. Perry upheld Strickland's order, and Anthony's attorneys appealed last week to the Fifth District Court of Appeals in Daytona Beach.

Anthony's attorneys did not respond to phone calls and emails seeking comment. But in a court filing Tuesday, they described the probation order as an "illegal sentence."

The Florida Department of Corrections has determined that Anthony had already served the probation sentence and that Strickland didn't have jurisdiction to clarify the order because the probation sentence was terminated, they said.