CALGARY — WestJet is warning customers after uncovering a scam involving a deeply discounted airfare offer for travellers headed to an upcoming conference in the United States.

The airline says the scam advertises return flights for up to 50 per cent lower than fares available through the WestJet website.

WestJet says as many as 100 conference-goers accepted the offer and paid for the airfare only to discover their ticket was invalid because it was actually bought with a stolen credit card.

The airline says it has turned over information regarding the scheme to police.

The latest fraud aimed at WestJet follows a telephone scam that involved fraudsters selling questionable holiday packages and suggesting those being called had won 999 WestJet dollars.