Police in Toronto are asking for the public's help to solve the riddle of a mysterious tunnel discovered more than a month ago. Investigations have so far been unable to determine who built the tunnel or its purpose, but its discovery has fueled security concerns ahead of the in Canada this summer.

During a news conference Tuesday, Toronto Deputy Police Chief Mark Saunders said the hand-dug tunnel is about 33 feet long and contained a gas-powered generator, moisture-resistant light bulbs, and food and beverage containers.

Saunders said the tunnel appeared to be well-constructed and that there were still tools inside, along with a wheelbarrow and a pulley system, when it was found. Police also found a rosary and a Remembrance Day poppy nailed to a wall.

But Saunders said the tunnel doesn't appear to go anywhere. There are questions about whether it was just unfinished or was it meant to be a single chamber.

There's also speculation about why it was built in the first place — was it for criminal purposes, such as drug smuggling or terrorism? Saunders told the news conference that it wasn't against the law to dig a hole.

According to the Canadian Broadcasting Corporation, it was a conservation officer who first discovered the tunnel. He noticed a large mound of dirt in a wooded area by tennis courts at York University, which is one venue for the games, on the north side of Toronto. He found that a piece of wood was covering a hole, and there was a ladder leading down into a chamber. The conservationist called the police.

Police have been investigating for more than a month but haven't come up with any answers. So on Tuesday they appealed to the public for help. According to the Toronto Sun, that's also when local leaders found about the tunnel. The newspaper says that neither Toronto's mayor, John Tory, nor Ontario's public safety minister, Yasir Naqvi, knew about the mysterious tunnel until the police announced it.

Naqvi says he does not believe the tunnel represents a security threat to the games in July and August, but that he will be receiving updates from the police going forward.

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