A man described as one of the ringleaders in the 2012 theft of $18.7 million worth of maple syrup has been sentenced to eight years in prison, but that term could be extended if he can't pay his multimillion-dollar fine.

On Friday, a Trois-Rivières, Que., judge handed Richard Vallières his eight-year sentence and fined him nearly $9.4 million.

If Vallières does not pay the fine, he will have to spend an additional six years behind bars.

The elaborate maple syrup robbery involved 3,000 tonnes of syrup from a warehouse belonging to the Federation of Quebec Maple Syrup Producers — the regulatory body that controls and manages the syrup trade.

The heist was discovered when a routine inventory check in July 2012 turned up an empty barrel that was supposed to be full of syrup. Officials with the federation quickly realized that dozens of its barrels contained not syrup, but water.

The resulting investigation by Quebec provincial police led to the arrests of 26 people.

Vallières was found guilty of theft, fraud and trafficking stolen goods. During his trial in Quebec Superior Court, he said that he had filled the barrels with water. His lawyer argued he had been coerced to fill the barrels with water by a man who carried a gun.

But witnesses called by the Crown painted him as one of the ringleaders of the heist.

Vallières's co-accused, his father Raymond, and a New Brunswick-based syrup reseller, Etienne St-Pierre, have also been found guilty for roles in the robbery.

All three men are appealing their convictions.