Greek police raided the Athens offices of Intellexa, an Israeli-owned company, and five other companies on Tuesday, according to local news outlet Kathimerini. Raids were also carried out in the houses of the company's CEOs.
Greece has been in turmoil in recent months after the disclosure of a political scandal related to the Predator software.
A local investigative journalist revealed this year that his phone had been tapped using the software, which was later found to have tracked opposition parties in Greece.
An international investigation, in which the Haaretz newspaper was involved, revealed a network of companies linked to Tal Dilian, a former officer and commander of an Israeli secret intelligence division, which acquired a variety of monitoring technologies and established a foothold for the European Union in Greece and Cyprus.
The investigation also revealed that a jet plane linked to Dilian transferred advanced spying technologies from the EU to a Sudanese militia.
Intellexa's Predator software
Last week, the New York Times reported that Greece granted Intellexa licenses to export its Predator software to Madagascar.
On Sunday, Documento, a Greek newspaper, revealed documents indicating that dozens of serving ministers, military officers, businessmen and media personnel were under the software's surveillance.
Intellexa is owned by the former commander of a secret Israeli intelligence division, Division 81. Unlike NSO, the company is not supervised by Israeli authorities.
The first lawsuit against Intellexa was filed in Greece in October and calls for a criminal investigation into the company.
Journalist Thanasis Koukakis filed the lawsuit with the Athens Prosecutor's Office, she accused the company and its staff of a series of criminal offenses, including violating privacy and communication laws.