Hundreds of letters have been sent to newly-registered users of a major new Vancouver-area bridge because the province said their accounts might have been compromised.

The B.C. Crown corporation that runs the Port Mann Bridge, between Coquitlam and Surrey, said it's taking precautionary measures after learning a customer service representative was not properly authorized.

Commuters looking for a smooth ride over the toll bridge have been signing up for special accounts since about mid-month, when the province announced those who got on board early would get a discount.

The Transportation Investment Corporation said it has sent letters to the 271 customers who might be affected, although it does not have evidence of any tampering.

The employee who handled customers' personal information was fired, the matter was referred to Coquitlam RCMP and the corporation says a full review of the incident is underway.

The 10-lane bridge is now partially open, with full operation to begin by end of 2013.