Mercedes has confirmed the team was fixing a hydraulic leak on Lewis Hamilton's car ahead of the Canadian Grand Prix.

The Briton's W10 suffered the problem after qualifying on Saturday in Montreal, but parc ferme conditions meant a repair job had to wait until today.

"Lewis's car has a hydraulic leak that we discovered late yesterday afternoon," a Mercedes spokesperson was quoted by Crash.net.

"We have diagnosed the source after the car came out of parc ferme and are now putting the car back together. We plan to be ready [for the race]."

It's an issue that will only increase worries at Mercedes after Lance Stroll also suffered a hydraulic leak during final practice resulting in a fiery failure.

And on the weekend when the 'Phase 2' engine was introduced for the works team and customers, the engineers at Brixworth will be hoping it is not an inherent flaw with their updated unit.

The work done to fix the issue has not resulted in any kind of penalty for Hamilton who starts second.