MONTREAL - The case of a former airport customs officer who was convicted Wednesday of accepting bribes from a drug-smuggling ring is an isolated one, says a Canada Border Services Agency spokesman.

Nancy Cedeno was found guilty by a judge of accepting cash in exchange for stamped customs forms as well as confidential codes used by agents at Pierre Elliott Trudeau International Airport to determine whose bags were checked.

But Quebec court Judge Claude Millette acquitted Cedeno of seven more serious charges, including conspiracy to import drugs, racketeering and gangsterism.

Millette said the Crown did not prove Cedeno knew she was working for the Mob when she helped the drug smugglers.

Cedeno, 34, was arrested as part of Operation Colisee in 2006, a four-year police investigation aimed at cracking down on the Montreal Mafia.

A relieved Cedeno smiled as she left Montreal courthouse.

She returns to court for sentencing arguments next Feb. 5.

The governmental agency entrusted with border security said smuggling incidents discovered during the Operation Colisee investigation as well as other cases have prompted stricter rules.

"We still treat these incidents as isolated cases and in our opinion it doesn't put any doubt on the integrity and professionalism of our officers," said Dominique McNeely, a CBSA spokesman.

"There are 7,200 border services officers who serve the Canadian public with the highest standards."

Police tracked bribes received by Cedeno through wiretaps and discovered she handed mules pre-stamped customs forms.

She also gave them a daily security code used by customs officials at the airport to decide which bags would be searched at the security gates.

The documents and numbers were given to her friend Omar Riahi, 33, a former fellow CBSA agent who in turn gave the codes to dealers.

By buying the codes from Cedeno, dealers were able to smuggle cocaine into Canada free of intense scrutiny.

Cedeno was on trial along with two other people alleged to have acted as couriers for the organization.

During her trial, Cedeno denied any knowledge of drug importation and testified she thought stolen goods were being brought into the country. But she didn't think Riahi, married with a child, would be involved in drug transactions.

The judge agreed.

"Nothing in the testimony, in the wiretap conversations or in the documentation produced formally shows that Ms. Cedeno knew the objective of the conspiracy - to import cocaine," Millette wrote.

Earlier this year, Riahi pleaded guilty to four charges: conspiracy, corruption and two counts of committing a crime for the profit of a criminal organization.

Riahi is due in court at the end of October for a sentencing hearing.

Cedeno was hired at the airport in 2003 and was recruited in 2005 by the ring.

The border services agency's new rules, implemented over the past few years, include more extensive background checks, routine verifications and new clearance procedures that require a periodic renewal.

"Our employees are already subject to a strict code of ethics and behaviour and any breach of the code is treated in accordance with the public service disciplinary rules," McNeely said.

Crown prosecutor Alexandre Dalmau says he is in favour of a prison term but he did not indicate what length. Cedeno's lawyer, Robert Bellefeuille, says he'll recommend a suspended sentence.