Sebastian Vettel and Red Bull should tread carefully in accusing the FIA of a conspiracy to enliven last weekend's Valencia race.

That is the view of Hans-Joachim Stuck, the president of the German motor sport association DMSB.

After Vettel retired at Valencia from a commanding lead, the reigning world champion and his team's Dr Helmut Marko suggested the FIA called the safety car period chiefly to close up the field.

"Vettel was too far ahead and so the field was brought back together," said Marko, doubting the safety car was needed to clear the track of debris.

Stuck however warned "Herr Vettel" to think in future before making accusations that could be interpreted as "unsportsmanlike conduct" -- behaviour that could draw the ire of the governing FIA.

"Sebastian Vettel should learn to be a good loser," he told Germany's Yahoo Eurosport.

"It was clear there was debris on the circuit, representing a danger of puncture to the other cars. For that reason, the safety car was justified," he said.

Stuck also scotched Vettel's claim that the safety car period caused his Red Bull to fail.

"I don't think driving slowly behind a pace car can be the cause of a failure, otherwise all the other cars would fail also.

"If the Red Bull car overheats because of the safety car then it is designed wrong," the former F1 driver insists.