BATHURST, N.B. -- The mother of a New Brunswick man fatally shot by police in Bathurst earlier this year has issued a public letter saying the grieving family isn't being provided adequate answers about what happened.

Michel Vienneau, 51, of Tracadie-Sheila was fired on in his vehicle near the Bathurst train station on Jan. 12, and Sylvie Vienneau says she and her husband, both in their 80s, can't understand why.

"Michel's death has caused insurmountable grief that has been impossible for us to manage causing us great waves of sadness, worry, anger and rage and a feeling of injustice for our family," she writes in the letter.

The Nova Scotia RCMP investigated the shooting, but have not released any findings and say the matter is now with the Public Prosecution Service of New Brunswick.

However, conflicting statements about what occurred have emerged in a lawsuit filed by Michel Vienneau's common-law partner, who was with him in the vehicle.

Annick Basque alleged in her July 13 statement of claim that Vienneau's death was caused by police negligence and that neither she nor Vienneau were involved in illegal activities.

In a statement of defence, the City of Bathurst says officers were investigating whether the couple were in possession of illegal drugs after returning from a trip to Quebec.

The statement also says the officers clearly identified themselves to Vienneau and had tried to stop his vehicle before it accelerated.

It says one police officer fired at the car as it moved towards another officer who was pinned against a snow bank.

None of the lawsuit's allegations or statements of defence have been proven in court.

Sylvie Vienneau's letter raises a series of questions about the police version of the shooting, asking why officers didn't simply arrest him when he came off the train.

"Why did they want to arrest our son, Michel? ... Where are these so-called drugs? Our son is not in the drug world. ... These are so many questions among many others that torture our family," the letter says.

"We have been left to imagine all kinds of scenarios to explain what happened to our son while we wait endlessly for no results, no answers and no response from authorities."

The mother said her son had no criminal record, was a well-known businessman and was respected in the community.

"I cry for our son every single day," she wrote.