An investigation into a suspected security breach at Toronto airport self-service kiosks has caused at least one airline to suspend the use of credit card information as a check-in option.

A spokesperson for WestJet told CTV.ca that customers now have to use their reservation number if they want to bypass the line-up at the counter for a boarding pass.

"We want to ensure our guests are protected and that their information is protected," said Gillian Bentley. "We thought it would be a proactive solution."

WestJet decided to take the step after a report surfaced in The Globe and Mail Wednesday that the financial community is investigating a number of frauds that occurred while people were using the self-service kiosks at Toronto Pearson International Airport.

"There's been no verified threat to our guests' information, but we want to make sure we take a prudent course of action to protect their information," said WestJet's vice-president of operations, Ken McKenzie. "That's why we're doing this."

Passengers have the option of using their credit card numbers, passport information or reservation numbers to get a boarding pass at the kiosk rather than wait in line to see an agent at a ticket counter.

Pearson, which accommodates more than 30 million passengers a year, has 150 of these kiosks at people's disposal.

Visa Canada, the company leading the investigation, issued a statement Wednesday saying they are looking into the situation and reminding their clients to monitor their credit card statements for irregular activities.

"We are working with airport officials and the airlines to investigate the situation," the company said. "As always, cardholders should regularly monitor their card accounts for suspicious or unusual activity and report it immediately to their card issuing financial institution."

A spokesperson for the Greater Toronto Airport Authority, the organization that manages Pearson, said there is full cooperation with investigators.

In an email to CTV News, spokesperson Scott Armstrong said that the GTAA network security had been audited and has been deemed safe and secure.

He also said that credit card information from self-serve kiosks are not collected or accessed by the GTAA, even though the airport authority owns the actual machines. It is the software providers and airlines that used the information for identification purposes.

He said because the investigation is ongoing, the GTAA can not comment about the proceedings or what prompted the investigation.

McKenzie said about 20 per cent of their customers who use the kiosks opt to check in with their credit card information.

He told CTV Newsnet it will be "a little bit of an inconvenience" for those customers but that the company thought it would be important to act now rather than act once the investigation was completed.

He also said that he wasn't aware of any personal information that had been compromised but that the company had been contacted by Visa and was asked to help them with their probe.