Nine people are facing charges over what authorities are calling the biggest gold theft in Canadian history from Toronto’s Pearson International Airport a year ago.

Peel Regional Police said that 6,600 gold bars worth more than 20 million Canadian dollars (£11.6 million) and 2.5 million (£1.4 million) in foreign currencies were stolen and the gold was melted down and used to purchase illegal firearms.

Those charged include an Air Canada warehouse employee and a former Air Canada manager who gave police a tour of cargo of the facility after the theft.

A jewellery store owner is also charged.

“This story is a sensational one and which probably, we jokingly say, belongs in a Netflix series,” Peel Regional Chief Nishan Duraiappah said.

Peel Regional Detective Sergeant Mike Mavity said the gold bars, weighing 419 kilograms (923lbs), and foreign currency, ordered from a refinery in Zurich, Switzerland, were transported in the haul of an Air Canada flight on April 17 last year.

He said that in the late afternoon a truck driver arrived at the airline’s cargo warehouse with a fraudulent bill that was provided to an airline warehouse attendant.

Det Sgt Mavity said a bill for seafood that was picked up the day before was used to pick up the gold.

The duplicate bill was printed off at the Air Canada warehouse, he said.

“They needed people within Air Canada to facilitate this theft,” Det Sgt Mavity said in front of the truck police say was used in the theft.

Det Sgt Mavity said police are searching for the Air Canada manager who gave police a tour of the facility in the days after the theft.

He said that manager left his job last summer and that they have an idea of where he is.

Det Sgt Mavity said some of the suspects were known to police and some were not.

He said they seized six crudely made bracelets made of gold.

“I don’t think I ever imagined they would have to deal with the largest gold heist in Canadian history,” said Patrick Brown, the mayor of Brampton, Ontario.

“It’s almost out of an Ocean’s Eleven movie or CSI.”

Air Canada employee Parmpal Sidhu, 54, from Brampton, Ontario; jewellery store owner Ali Raza, 37, from Toronto; Amit Jalota, 40, an Oakville, Ontario resident; Ammad Chaudhary, 43, from Georgetown, Ontario; and Prasath Paramalingam, 35, from Brampton, are among those that have been arrested.

Det Sgt Mavity said they have been released on bail conditions and will be in court at a later date.

He said the truck driver that allegedly picked up the gold, Durante King-Mclean, a 25-year-old from Brampton, is currently in custody in the US on firearms and trafficking-related charges.

Police are searching for former Air Canada manager Simran Preet Panesar, 31, from Brampton, as well as Archit Grover, 36, from Brampton, and Arsalan Chaudhary, 42, from Mississauga, Ontario.

Peel Regional Deputy Chief Nick Milinovich said only 90,000 Canadian dollars (£52,400) of the more than 20 million Canadian dollars has been recovered.

US ATF special agent Eric DeGree said King-Mclean was arrested in Pennsylvania after a traffic stop and that led to the seizure of 65 illegal firearms that were allegedly destined to be smuggled into Canada.

Mr DeGree said he tried to flee after police discovered the firearms in his rental car.

Brink’s, an American cash handling company, arrived at the airport cargo facility on the night of April 17 to pick up the gold and was told the gold and currency was missing after a search.

Brink’s sued Air Canada over the theft last year.

According to the company’s filing last year, a thief walked away with the costly cargo after presenting a fake document at an Air Canada warehouse on April 17.

In a November 8 statement of defence, Air Canada rejected “each and every allegation” in the Brink’s lawsuit, saying it fulfilled its carriage contracts and denying any improper or “careless” conduct.

The country’s largest airline also said Brink’s failed to note the value of the haul on the waybill – a document typically issued by a carrier with details of the shipment – and that if Brink’s did suffer losses, a multilateral treaty known as the Montreal Convention would cap Air Canada’s liability.

In Federal Court filings that claim breach of contract and millions of dollars in damages, Brink’s said an “unidentified individual” gained access to the airline’s cargo warehouse and presented a “fraudulent” waybill shortly after an Air Canada flight from Zurich landed at Pearson.

The statement of the claim says the staff then handed over 400 kilograms of gold in the form of 24 bars plus nearly two million dollars in cash to the thief, who promptly “absconded with the cargo”.

Mr DeGree said dozens of firearms authorities were seized, including two fully automatic weapons and five guns that were untraceable.

“I’m proud to say that we successfully put an international gun trafficking operation out of business. We kept 65 firearms off the streets of Canada and prevented them from being used in any number of crimes,” Mr DeGree said.

Det Sgt Mavity said that “we believe they melted down the gold and with the profits they got from the gold they used to purchase illegal firearms”.