Ottawa Police have charged a young, part time bank teller with a series of offences. It comes after a lengthy investigation that uncovered 9 bank clients stripped of hundreds of thousands of dollars. It's the kind of crime that could shake your confidence in the banking system. But police say it was the timely actions of other bank employees across this country that helped prevent the theft of even more money.

Over a period of 10 to 12 weeks, Ottawa Police allege a bank teller used his position to access the information of 9 bank clients in Ottawa and pass that information on to criminals working in both Edmonton and Toronto. Sources tell CTV News the teller worked for the Bank of Montreal.

“At this point, the bank lost over $320,000,” says Sergeant Steven Desjourdy, the lead investigator on the case with the Organized Fraud Unit of the Ottawa Police, “All the clients were reimbursed and because of good employee training and detecting, another $360,000 (in theft) was prevented.”

This is how it works. It's called an account takeover. Fraudsters use fake ID based on stolen banking information to access those accounts.

“In this case, fraudsters would go into the bank and say they lost their debit card so they'd ask for new card and get a new PIN.”

Desjourdy says the fraudsters were actually in the bank at the counter with their fake ID’s, with all their victims’ information, and about to do transactions from one account to another totaling $360,000 when bank investigators intervened. After further examination, those investigators noticed that while the thefts were occurring outside of Ottawa, in Toronto and Edmonton, all the bank clients were in Ottawa, linked to one common employee.

In mid-December, police charged 24-year-old Osman Wais, a part-time bank teller with 9 counts of fraud over $5,000, along with conspiracy to commit, possession of property obtained by crime and unauthorized use of a computer.

In a statement, the Bank of Montreal said that protecting its clients is a top priority.

“We have notified the affected clients, reimbursed them for their losses and are taking enhanced security measures with their accounts,” said Julie Smithers with BMO Financial Group, “Additionally, we have reported this matter to the Ottawa Police and continue to work closely with them."

“I would have thought banks would be more secure and safer for people to be involved with,” says one man outside a BMO branch in Ottawa.

“Human nature is human nature,” added another customer, “It's not determined by where you work. No matter how you vet people for positions, you're going to find this kind of thing.”

Sgt. Desjourdy says those involved may think this is a minor victimless crime, just passing along paperwork, but he equates it to a bank robbery, minus the gun.

The victims have all been reimbursed by BMO though the bank has not reclaimed its money. Police are still trying to figure out who the main players are.

Osman Wais’ first court appearance is January 24th. None of the allegations have been proven in court.