Oct.7 (GMM) F1's safety car rules have been freed up ahead of the Chinese grand prix.

After the rain-drenched race at Fuji Speedway a week ago, Lewis Hamilton came under fire for driving erratically as he led the pack behind the safety car.

His behaviour was probed by the stewards, who found that - according to the letter of the current rules - the British championship leader perhaps should have been punished.

But race director Charlie Whiting is reported to have said by Auto Motor und Sport: "If Hamilton had done something wrong, then he would have had to punish ten other drivers."

Stewards in Shanghai have now advised that, behind the safety car in wet conditions, drivers are recommended to keep a distance of ten car lengths to the car in front, rather than the previous five.

In the drivers' briefing in China, meanwhile, the field has also been warned to behave more judiciously in difficult conditions in the future, including keeping a consistent pace.

Pole sitter Hamilton says the rules are now clearer.

"I think we understand a little bit better but I put my hand up and perhaps I didn't do the best job under the safety car in the wet," he said.

"It was tricky for everyone, visibility was the biggest problem but I think we have a better idea."