The public prosecutor's office in Nancy, France, confirmed Schneider's disappearance on Thursday, according to Luxembourgish radio station Radio 100,7.

Schneider, a former intelligence operative for the Luxembourgish government, was arrested two years ago in France on suspicion of fraud relating to cryptocurrency OneCoin.

He was due to be extradited to the US and had been on house arrest prior to his disappearance.

The authorities were alerted to his disappearance after his electronic tag ceased to work, say reports.