Jenson Button escaped injury after he crashed heavily in free practice for the Monaco Grand Prix although he was taken to hospital for precautionary tests.

The BAR driver, third fastest in Thursday's qualifying, skidded sideways as he exited the tunnel in the second session of the morning and slammed at speed into the tyre barrier before the chicane. The session was immediately halted.

Button remained in his shattered car for 10 minutes on Saturday while doctors attended to him with an ambulance waiting nearby.

His father John Button said that team boss David Richards had called to say the 23-year-old Briton was unhurt.

He was taken to the Princess Grace hospital for further checks only three hours before the start of final qualifying for Sunday's race around the streets of the Mediterranean principality.

It was not immediately clear whether Button would be allowed to return for qualifying.

Doctors said Button had remained fully conscious with no visible injuries but had been winded by the heavy side impact at one of the fastest parts of the circuit.

Austrian Karl Wendlinger had a huge smash at the same point in practice for the 1994 race and was in a coma for days afterwards. Although he returned to the track next year, it effectively ended his career.

The track has since been redesigned and safety improved considerably since that incident.