A "substantial" reward is being offered for the return of more than a million dollars worth of jewels -- including two Stanley Cup rings -- that were stolen from one of Canada's most influential families.

A spokesperson for the Bronfman family said Monday that the amount of the reward would have to be negotiated and that the person's anonymity would be honoured.

Mark Mendelson, a former Toronto police officer, said that the Bronfmans are hoping that greed will prompt those who took the jewels to return them for the cash reward.

"Certainly the people that took this took it for greed and hopefully they'll be curious enough to find out what that property is worth to the family," he told reporters at a news conference. "Our hope is that the same greed will be the catalyst for them to return the jewels."

The jewels, which include two Montreal Canadiens Stanley Cup rings, a flawless six-carat diamond and other family heirlooms, were stolen from the Bronfmans' mansion in Toronto's tony Forest Hill neighbourhood on November 8. The goods are estimated to be worth about $1 million.

The Bronfman family -- which initially became famous for its holdings in the liquor business, particularly Seagrams -- owned the Canadiens in the 1970s when the team won the Stanley Cup.

Police believe thieves got past a locked iron gate, security cameras, entered a second-floor window without a ladder and removed a 200-pound safe that contained the 59 pieces of jewelry and cash.

Mendelson, who now works as a private investigator, said the thieves clearly knew what they were doing.

"This certainly isn't your run-of-the-mill break-and-enter where kids break into your home for a bottle of booze and some spare change sitting in a cup," he said. "Certainly these people are sophisticated and knew what they were doing."

However, he warned the thieves they would have a hard time selling the jewelry.

"I would suggest that it's very difficult right now to move this stuff, and if (someone is) in possession of it, we're offering a very simple alternative to selling this jewelry on the black market," he said.

The Bronfmans' reward offer is separate from the ongoing police investigation. Mendelson said the Bronfmans would be thrilled to have a suspect arrested but that they are willing to keep the person's anonymity if they were to return the jewels intact.

Anyone with information can call 1-647-299-1491 or visit www.bronfmanjewellery.com, which contains photographs of the stolen items.

With files from The Canadian Press