OTTAWA - The Canadian Security Intelligence Service makes a "disconcerting" number of mistakes in applications for eavesdropping warrants, raising potential concerns about liberties and privacy, says a watchdog over the spy agency.

In a top secret report, CSIS Inspector General Eva Plunkett criticizes the agency for failing to comply with policy, a lack of written documentation on important matters and gaps in the service rules.

Plunkett said in an interview the spy service hasn't moved quickly enough to create up-to-date guidelines for an era when it is operating around the world against terrorism, not just keeping an eye on spies at home.

"Any organization has a hard time keeping its policies up to date," she said.

"But when you have the kind of intrusive powers that the service has, I think it's essential that there's a guidebook for people to follow."

A declassified version of Plunkett's report to Public Safety Minister Peter Van Loan for 2007-08 was obtained by The Canadian Press under the Access to Information Act.

As inspector general, Plunkett serves as the minister's "eyes and ears" on the spy agency.

Overall, Plunkett found CSIS did not act beyond its legal authority, nor did it contravene any ministerial directions or exercise its powers "unreasonably or unnecessarily."

But Plunkett, now in her sixth year as inspector general, found more instances of failure to comply with CSIS operational policy than in her previous four reports, as well as a higher level of errors in CSIS records.

The cases of non-compliance involved "key core activities" of the service, including one violation related to execution of a surveillance warrant.

Further she found the rate of errors in material CSIS presents to the Federal Court to obtain electronic or physical surveillance warrants "continues to be disconcerting."

In 2005 the court dismissed an application for a warrant due to the service's failure to disclose full, fair and accurate information.

CSIS has since taken a number of measures to reduce mistakes.

"The service fully agrees that accuracy in its information is absolutely essential," said spokeswoman Manon Berube.

"The CSIS director and executive place a high degree of importance on such accuracy and vigilance in ensuring proper record-keeping and information accuracy. Discrepancies are corrected as soon as they are identified."

In her report, Plunkett clearly flags for Van Loan the importance of faithful representations to the court. "This is an area that merits close monitoring for you during the coming year given the intrusive investigative authorities provided by warrants and the implications of these authorities on the civil liberties and privacy interests of individuals."

Plunkett's report says she was "quite troubled" at being unable to find key documentation in CSIS files.

In one case CSIS assured her that agency director Jim Judd had briefed the minister verbally on an issue that might stir public controversy, "however, no written briefing materials or other documentation could be provided to validate this fact."

Plunkett said that, while some gaps in CSIS policy have been addressed, others "of critical importance" remain outstanding.

It is well known that the spy agency operates abroad in support of the fight against terrorism, including Canadian military efforts in Afghanistan. But many CSIS policies were written for a different time.

"The world has changed. It's a different game than it was," Plunkett said. "Combatting terrorism isn't quite the same as espionage and counter-intelligence."

Plunkett says she is continually impressed by the calibre and dedication of CSIS employees

"I think they're generally good people trying to do good work. But they're people, and people make mistakes."