OTTAWA -- Air Canada was solely to blame for an airport foulup that allowed 209 international passengers and crew to walk off a flight without being checked by customs, internal documents indicate. The travellers from London were misdirected Oct. 12 to the domestic arrivals area in a major security breach on the opening day of the newly refurbished MacDonald-Cartier airport in Ottawa.

Customs officials had to chase the dispersing passengers, some of them already outside the building, and herd them back for clearance.

Even so, one passenger disappeared and couldn't be contacted for another nine days. The unidentified man travelled to the United States in the meantime and was eventually allowed to make a declaration by telephone that he had no contraband goods.

"Some confusion might have existed, as this was the opening day of the new airport facility," says material obtained under the Access to Information Act from the Canada Customs and Revenue Agency.

An internal investigation confirmed Air Canada was entirely responsible for the breach, even though an airline official said at the time that the problem originated with customs.

Air Canada's Laura Cooke said yesterday the incident was "reflective of the challenges airlines face in the first day at a new airport facility. But since that time, we have reviewed procedures with our employees."

Investigators determined that all the signs used to direct passenger flow at the airport were appropriate and didn't need to be changed. The $165-million expansion at the facility uses a flexible gate and departure-lounge system so they can be used for international and domestic flights as needed.

The censored material indicates that Air Canada attended daily pre-opening briefings "held to work out problems associated with the new terminal" and should have been fully aware of the changed layout.

Although customs officials initially played down the incident, the department diverted staff for the next two months to observe arriving flights that they deemed high-risk to ensure all airlines at the Ottawa airport were complying with the law.

Pierre Marquis, speaking for Canada Customs, said there were no further incidents and the department now carries out spot checks only.

Air Canada allegedly violated Section 11(3) of the Customs Act, requiring airlines to direct international passengers to the customs area, and faced penalties of up to $100 for each passenger -- $20,900 in the case of the Ottawa incident.

"Customs is not even close to the area where they disembark," said Marquis, adding Air Canada is "answerable." He declined to indicate whether Air Canada was fined.

"This is a matter between us and the carrier," Marquis said. "It's not something that we divulge publicly."

However, Cooke said a penalty was indeed levied against the airline -- she would not disclose the amount -- but that Air Canada intends to challenge the decision.

The man who slipped through unchecked immediately took a business trip by car to the United States. Determined by officials to be a low-risk passenger because he had no previous violations, he made an oral customs declaration over the telephone Oct. 21.

Cooke noted Air Canada did direct the checked passenger luggage of the Oct. 12 flight properly to customs.