QUEBEC, Canada (AP) — Police in Quebec were following the scent of something sweet — millions of dollars' worth of maple syrup missing from a large warehouse stocking over $30 million worth of the amber nectar.

The theft puts a cavity-sized dent in Quebec's syrup stock, considered to be a global strategic reserve of the sweet stuff that is often used to replenish markets during disappointing seasons. Quebec produces up to 80 per cent of the world's maple syrup.

Quebec Provincial Seargeant Claude Denis said Friday it was too soon to determine the exact quantity or value of the maple syrup stolen from the St Louis-De-Blandford facility where over 10 million pounds (4.54 million kilograms) is stored.

The Federation of Quebec Maple Syrup Producers said it discovered the missing syrup last week during a routine inventory where empty barrels were found at the site at St Louis-de-Blandford, Quebec. Officials initially kept the news quiet, hoping it would help police solve the crime.

Anne-Marie Granger Godbout, the executive director of the federation, said that while it isn't unusual for individual maple syrup producers to have stock stolen, having millions worth of syrup stolen is "unusual".

"It's the first time something like this has happened," she said. "We've never seen a robbery of this magnitude."

She said the disappearance of the stock wasn't obvious at first in the huge warehouse. The facility alone houses nearly the equivalent of half the entire US production of maple syrup in a year, she said.

"The US is the main market for maple syrup, about 75 per cent of Canadian maple syrup is directly exported to the US," she added. She noted that the theft was particularly ill-timed after a disappointing 2012 season for US producers, triggering more demand for Canadian syrup.

She said auditors would require a few more days to determine how many of the 45-gallon barrels have been emptied.