The group operating Pearson International Airport says it has revoked the escort privileges of the RCMP officers who accompanied two federal politicians who went to the Toronto airport to check security earlier this week.

Transport Minister John Baird and Liberal Senator Colin Kenny spent half an hour in restricted areas on the tarmac on Sunday, the Globe and Mail reports.

Transport Canada is investigating the incident.

The politicians, who were dressed in windbreakers and baseball hats, said they spoke with airport staff but were never questioned about how they had gained access to the tarmac.

But the Greater Toronto Airports Authority said Thursday that Kenny, chair of the Senate's national security committee, and Baird were under RCMP escort and had temporary passes to enter restricted areas.

"Preliminary reports from the minister and the senator indicate that their police escorts did not maintain visual contact at all times," the authority said, explaining its decision to revoke the RCMP officers' escort privileges.

If visual contact is lost, police are required to notify the GTAA immediately, said the authority.

Kenney told the newspaper the passes the GTAA gave them went unchecked and were "irrelevant to getting on the tarmac."

GTAA officials said they are concerned with the characterization of the incident as a security breach since Kenney and Baird were issued passes and were under the supervision of the RCMP.