Somebody stole gold and other valuables worth $15 million from Canada's busiest airport, police said

• Thieves made off from Toronto Pearson airport with gold and valuables worth $15 million, police said.
• The gold was part of an intra-bank trade involving TD Bank, per a memo seen by the Toronto Sun.

Police are investigating a "very rare" heist in which gold and other valuables worth more than C$20 million (about $15 million) were stolen from Canada's busiest airport.

Peel Regional Police inspector Stephen Duivesteyn told outlets including CBC that a plane carrying a container with gold and other items "of monetary value" arrived at Toronto Pearson Airport Monday night.

"Once this cargo was offloaded at a holding facility subsequent to its arrival, this high-value container was removed by illegal means from the holding facility," he said.

Police were continuing to investigate the theft. "I would suggest this as an isolated incident – this is very rare," Duivesteyn said.

Pearson often handles gold shipments such as bullion from mines in northern Ontario.

It is also one of the world's top 30 cargo airports and handles close to half of Canada's air cargo, according to its website.

A confidential memo obtained by the Toronto Sun suggested that the gold was likely part of an intra-bank transaction including TD Bank, while the airline involved was Air Canada.

Sources told the Sun that the full shipment comprised 3,600 pounds of gold, worth about $100 million, suggesting the thieves only escaped with a portion of the cargo.

Another source told the newspaper that the heist was probably carried out with inside help, while other sources suggested that organized crime could have been involved.

A representative for the Greater Toronto Airports Authority, which operates Pearson, told Insider: "Thieves accessed the public side of a warehouse that is leased to a third party, outside of our primary security line. This did not involve access to Toronto Pearson itself and did not pose a threat to passengers or GTAA staff."

Air Canada told the Sun it had "no information to provide" and TD Bank didn't respond to its requests for comment.

Air Canada, and TD Bank didn't immediately respond to requests for comment from Insider, made outside normal working hours.