Former socialist health minister Andreas Loverdos, who has been implicated in an alleged bribery scandal involving Swiss pharmaceutical firm Novartis, filed lawsuits on Monday against all the witnesses - including the protected - who testified against him in the ongoing probe.
In his lawsuit, Loverdos claims he is facing trumped-up charges, described the probe as a" frame-up" and accused the witnesses of slander and perjury.
His lawyer, Angelos Karahalios, said his client may submit new lawsuits soon.
Loverdos, an MP with Movement for Change (formerly PASOK), is being investigated in connection with alleged bribes during his term as health minister from April 2011 to May 2012.
He is scheduled to face a corruption prosecutor on May 30.