Federal police were investigating Thursday the alleged poisoning deaths of millions of bees in the Canadian prairies.

These were "highly suspicious deaths," Royal Canadian Mounted Police (RCMP) Corporal Mike Boychuk told AFP by telephone from Brandon, Manitoba.

A probe was launched after a beekeeper complained to authorities that more than 200 hives at two locations north of Brandon had been targeted in the last weeks of August.

The exact number of bees killed is not known, but it is estimated to be as high as 10 million, as a typical hive holds between 10,000 and 60,000 bees -- with the count peaking mid-summer.

"All of the bees died at the same time, and a crystalized substance was found at their hives," said Boychuk.

The substance is now being analyzed by the RCMP crime lab to determine what it is, and whether the deaths are due to foul play.

Police said they have no suspects at the moment.

A conviction for causing unnecessary suffering to an animal (birds and bees included) carries a maximum penalty of five years in jail and a fine of Can$10,000 ($9,138).

This beekeeper, meanwhile, has lost tens of thousands of dollars worth of bees and potential earnings from pollinating area crops and honey sales.

Sudden bee deaths -- linked to pesticides and parasites - have provoked worldwide concern in recent years, as these insects are crucial for agriculture.

Honey supplies have fallen this year partly due to a record drought in California.

Meanwhile in Canada's Ontario province, beekeepers this month launched a half-billion-dollar lawsuit against pesticide makers. The case marks an escalation of tensions between beekeepers and chemical companies, two groups which farmers rely on for pollination and crop protection.