The professor’s ex-wife, who has denied any wrongdoing, her Greek partner, and three other people – one Bulgarian and two Albanian nationals – were arrested yesterday evening over the incident, a police official said today.

The woman’s partner has confessed to shooting the academic, a 43-year-old Polish national, according to the official.

The rest of the detainees are accused of assisting him.

The weapon used in the killing has not been found.

The suspects were expected to respond to the charges, which have yet to be disclosed, this week.

Greek authorities have not released the names of the individuals alleged to be involved in the incident.

The professor was shot in the chest and the back on July 4, in the northeastern suburb of Agia Paraskevi, according to a confidential police document seen by Reuters.

Police later found six bullet shells and a shotgun cartridge at the crime scene, the document said.

Some of the suspects escaped in a luxury car, according to video footage collected by the police as part of the investigation.

They were later detained by police acting on arrest warrants.