Renault pointed to a fuel leak as the reason Kevin Magnussen's car caught fire during first practice at the Malaysian Grand Prix.

The Dane was in the pits when the fire from his car started, taking several minutes to be controlled.

Renault technical director Nick Chester said Magnussen had avoided injury, and believes the team have found the reason for the incident.

"We had a fuel leak from a breather," he told Sky Sports.

"It looks like the tank pressurised, but we will investigate. We were running the tank full and we were running some experimental parts really in preparation for Mexico, so different set-up to the other car.

"Everyone's OK, that's the main thing.

"Fortunately the car doesn't seem to be too badly damaged so we'll try and get it out for P2. There is obviously a fair bit of work to do, and a fair bit to clean, but we'll try to get him out for as much of the session as we can."

Mercedes duo Nico Rosberg and Lewis Hamilton topped the timesheets in opening practice.