Thieves in Quebec have made off with a massive haul of maple syrup worth up to $30 million in an unusual burglary targeting the world's most important association of producers of the Canadian confection.

Quebec provincial police are investigating after the Federation of Quebec Maple Syrup Producers, in an inventory check of one of its warehouses, noticed that a large number of the barrels it uses to store its maple syrup were empty.

The warehouse, in St-Louis-de-Blandford, 160 kilometres northeast of Montreal, held about 3.4 million litres of bulk maple syrup and is part of a global strategic reserve of the sticky liquid.

The federation of producers said the Sûreté du Québec and an auditing firm are determining exactly how much the thieves took.

"The St-Louis-de-Blandford warehouse had been secured by a fence and locks, and visited regularly," federation president Serge Beaulieu said in a news release.

The statement said the syrup was being held at the warehouse temporarily while the finishing touches are put on a new storage facility in nearby Laurierville, Que. It was supposed to be transferred over the coming weeks.

Insured

If the entire warehouse's contents were stolen, it would represent more than a tenth of Quebec's 2012 harvest, and more than a quarter of the federation's inventory.

The stock of syrup was insured, the federation said, so its members will not lose financially.

The Federation of Quebec Maple Syrup Producers is the industry association for the province's 7,500 producers, and administers a bulk sale system with quotas on individual operations. The federation also keeps nearly 13 million litres in syrup in three warehouses to stabilize global supply and prices.

Quebec produces three-quarters of the world's maple syrup. The province's output hit 33 million litres this year, down about five per cent from last year but way up from the lean harvest of 2008.