A mysterious seven-metre tunnel containing tools, lights, and a generator was discovered in woodland near York University in January, CBC News is reporting. The underground passageway had reinforced walls and was tall enough for a person to stand up in.

According to the CBC, a Toronto and Region Conservation Authority employee found the entrance beneath a sheet of corrugated metal last month. It appeared to have been dug using a shovel over a number of weeks, possibly months, by persons unknown.

After a police investigation that ruled out possible use as a drug lab, the tunnel was filled in.

Right now, it's a mystery who built the tunnel, but the cops are not taking the matter lightly. National security officials have been notified due to its location close to the Rexall Centre, a Pan Am Games venue.

A news conference on the matter is expected tomorrow.

Until then, feel free to speculate wildly. Maybe it has something to do with Drake. Or poutine. Or deadmau5.

Chris Bateman is a staff writer at blogTO. Follow him on Twitter at @chrisbateman.