Click photo to enlarge
Monaco's honorary Polish consul, Wojciech Janowski, partially hidden, leaves in a car the Nice police station, southeastern France , Friday, June 27, 2014. Janowski is suspected by investigators of having ordered the murder of his step-mother, Helene Pastor, a real-estate heiress in Monaco, last May 6 in Nice. Pastor and her driver died some days later. (AP Photo/Lionel Cironneau)

PARIS (AP) — Prosecutors say a Polish diplomat has acknowledged ordering the killing of his mother-in-law, a Monaco real estate heiress, to profit from the inheritance.

The shooting of Helene Pastor and her chauffeur on May 6 has shaken up the exclusive Mediterranean principality.

Marseille Prosecutor Brice Robin said Friday that Monaco's honorary Polish consul, Wojciech Janowski, acknowledged plotting the killing "to stop the suffering" of his wife, Sylvia Pastor. He didn't elaborate.

The prosecutor said Sylvia Pastor had no idea about her husband's plot against her mother.

Robin said the motive appeared linked to inheritance money. He said Janowski paid a gym instructor 250,000 euros ($340,000) to find hit men and organize the killing.

He said the diplomat, the gym instructor and five others are being handed preliminary charges in the case.