Sarkozy only began serving a five-year prison sentence at the end of October. He was convicted in September of financing his 2007 presidential campaign with financial support from Muammar Gaddafi's Libya.
During Monday's hearing, Sarkozy described the case as a nightmare.
"I could never have imagined that at the age of 70 I would have to experience being imprisoned," he said via link from the La Santé institution.
This pain has been forced upon me, and I live with it. It is very, very difficult.
He will now be supervised but free while awaiting his appeal in a new trial, which is expected this spring at the earliest.
