Swiss-French banker Jean-Claude Oswald, who is facing charges of money laundering and bribery in connection to an arms procurement program, went missing on Tuesday after removing his monitoring bracelet, Greece's Justice Ministry said.
Oswald, who appeared in an Athens court earlier in the day where his case was being heard, destroyed the device's strap and disappeared, it said.
Police has launched a manhunt to recapture him.
The suspect is alleged to have played a key role in securing kickbacks in the Siemens bribery scandal and a series of defense deals including the procurement of submarines.
He had been indicted along with 11 other people in connection with kickbacks allegedly pocketed from the acquisition of self-propelled howitzers manufactured by German firm Krauss-Maffei Wegmann (KMW).
Oswald was extradited to Greece in 2015 following his arrest in Abu Dhabi.