OTTAWA -- Canada's privacy czar says police surveillance of a Montreal journalist's phone suggests a need for clearer laws.

Daniel Therrien tells a Commons committee that Parliament has a role to play in guiding the courts on when to grant police a warrant to obtain sensitive data.

Montreal-based La Presse newspaper said this week it had learned at least 24 surveillance warrants were issued for columnist Patrick Lagace's iPhone this year at the request of city's police service.

The surveillance flowed from an internal probe into allegations police anti-gang investigators fabricated evidence.

Three warrants reportedly authorized police to get the phone numbers for all Lagace's incoming and outgoing texts and calls, while another allowed them to track the phone's location via its GPS chip.

Therrien says while judicial involvement in issuing the warrants is a good start, it's not adequate in itself -- and it may be useful to give the courts new tools to better exercise their powers.