Crews working on the reconstruction of Toronto's iconic Maple Leaf Gardens have found something that just might be a historical treasure — but exactly what it is remains a mystery.

Maple Leaf Gardens was built in the midst of the Depression and opened its doors on Carlton Street in 1931.

For more than 60 years the hockey team, which bears the same name as the building, played on its ice — until February of 1999 when the team moved to the Air Canada Centre.

Maple Leaf Gardens is now being reconstructed, remodelled and refurbished, to make it into a giant Loblaws grocery store, as well as an athletic centre for Toronto's Ryerson University.

But recently, when crews were removing some stone flooring near the old entrance they found something.

According to Randall Gwizd who was working on the site, it was bricklayers who discovered the treasure.

"All I know is what the super[intendent] told me. The bricklayers found it by the front doors underneath the stone that marks the name of the building and they lifted it up and found the time capsule."

Gwizd said the workers found the capsule as well as "a rule book from 1931, a newspaper and I think something else."

"Loblaws came down and took [the capsule] right away," said Gwizd "Nobody really got to see it."

In an email statement to CBC News Loblaws confirmed it had taken possession of the capsule but wouldn't say much more.

"Thanks for your enquiry. We have found articles during construction, but they are currently being assessed and validated. We will be in touch once we have more information. Thanks for your interest," the company said.

Phil Pritchard, curator at the Hockey Hall of Fame, had no idea the time capsule existed but he's excited to think about what might be inside.

"When I heard about it this morning it was pretty amazing," he told CBC News. "I want to be in line. If there are hockey pieces we'd love to have them here."

Gwizd says he'd like to see the time capsule passed along to the Hall of Fame too, "because it's hockey history, right? Everybody should see it."