Canada court says country's spy agency illegally retained data

A vehicle passes a sign outside the Canadian Security Intelligence Service (CSIS) headquarters in Ottawa in this November 5, 2014 file photo. REUTERS/Chris Wattie

OTTAWA (Reuters) - A court dealt Canada's spy agency a blow on Thursday, declaring it had illegally kept data collected during investigations over the past decade and threatening sanctions if the issue occurred again.

Although judges have previously criticized the Canadian Security Intelligence Service, or CSIS, for a lack of openness about its operations, the ruling was particularly uncompromising.