Poland’s former honorary consul in Monaco has been sentenced to life in prison for the murder of the principality’s wealthiest woman, Hélène Pastor.

A French court handed a life sentence to the Polish son-in-law, Wojciech Janowski, who ordered her murder. It is believed to be done so as to acquire the inheritance.

Dubbed as Monaco’s “other princess”, Mrs Pastor, a 77-year-old at the helm of a €12bn real estate empire, was gunned down along with her longstanding butler and chauffeur, Mohamed Darwich, in Nice on May 6, 2014.

She died from wounds sustained when a gunman fired through the windows of her car. Her chauffeur scummed to his injuries four days after the attack.

The court handed sentences to Janowski, former partner of Mrs Pastor’s daughter Sylvie. The gunman, Samine Said Ahmed, and his lookout, Al Hair Hamadi, were also handed life sentences.

Initial police questioning reveals that Janowski had confessed to the crime. He also confessed to paying his fitness coach a sum of €140,000 to take her out.

He had alleged that Hélène Pastor and her son, Gildo had made her daughter’s life a misery. And as such, it was his moral duty to put an end to it.

Speaking to the investigators, he said: “How many times did I find Sylvia in pieces? (The murder) was to put a stop to the suffering of my wife.”

However, he later changed his wording, citing his “poor French”. He said that he had misunderstood the questions and pleaded innocent.

He goes on to say that, Mr Dauriac, his personal trainer, was the one who had ordered the murder and then pressured him into paying “protection money” or see his children kidnapped.

Dauriac said Janowski first mentioned the hit in 2012 and again in 2013, when Sylvia became ill.

“This cannot go on, Sylvia’s illness has deteriorated, we have to get rid of the old woman. Can you help me?” Dauriac quoted Janowski as asking him.

Just before the verdict, Janowski expressed his “apologies” to his ex-wife and children in the court.

The lawyer of Janowski said that he planned to appeal the ruling.