A total of $20 million worth of gold and other high-value goods have been stolen after being offloaded from an aircraft at Toronto Pearson International Airport, police say.

Peel Regional Police said the heist occurred on Monday when a "high-value container" was stolen from a holding cargo facility after it was taken off a plane that landed at the airport. 

"An aircraft arrived here at the airport in the early evening. As per normal procedure, the aircraft was unloaded and cargo was transported from the aircraft to a holding cargo facility,"  Inspector Stephen Duivesteyn said while announcing the theft.

Duivesteyn said after the cargo was secured in the holding facility, it was removed by "illegal means." The container was holding gold and other "high-value goods" worth $20 million. 

HEIST AT PEARSON AIRPORT 'VERY RARE'

The missing goods were reported to police a short time later. Police would not say what airline was responsible for shipping the cargo or where the plane arrived from.

"This is very rare," Duivesteyn said, adding that it's too early to know if the theft was carried out professionally. 

Police also said they don't know where the gold is or if it's still in the country. Police said they believe this is an isolated incident.

"Our goal is to solve this theft," Duivesteyn said. "We want to solve it ...For the public worried about flying out, there should be no concern. We do not consider this a public safety matter."

No arrests have been made and police did not release any information on suspects. 

“We are three days in, so our investigators have their eyes open to all avenues," Duivesteyn said.

The Greater Toronto Airports Authority confirmed to CTV News Toronto in a brief statement they are aware of the theft that occurred earlier this week.

"The GTAA wishes to clarify that thieves accessed the public side of a warehouse that is leased to a third party, outside of our primary security line," the statement reads. "This did not involve access to Toronto Pearson itself and did not pose a threat to passengers or GTAA staff."