Red Bull boss says rumours of a conspiracy against Mark Webber "complete rubbish"

THE rumour mill went into overdrive after the wheels literally came off Mark Webber's Chinese Grand Prix campaign.

MOTORSPORT: The rumour mill went into overdrive after the wheels literally came off Mark Webber's Chinese Grand Prix campaign.

Porsche denied reports they had signed the Formula One driver on a five-year enduro sportscar deal from next year after the Australian's wretched weekend in Shanghai was ultimately ended by a loose rear wheel.

And Red Bull team principal Christian Horner furiously denied there was anything untoward behind Webber's horror run, describing rumours of a conspiracy against the Australian as "complete rubbish".

Rumours linking Webber with a move to Porsche first emerged last year but regained momentum after Red Bull's Sebastian Vettel ignored team orders and denied the Australian victory in Malaysia.

Webber, 36, left Sepang contemplating his Formula One future and he appeared to have made up his mind after Radio Le Mans claimed yesterday the Australian had officially signed the Porsche deal.

A career change must have looked tempting after his shocking Shanghai run.

Webber was demoted to the back of the race grid after his car ran out of fuel during the qualifying session.

After starting Sunday's race from pit lane, Webber had eighth place in sight by lap 15 but collided with Toro Rosso's Jean-Eric Vergne, earning a three-place grid penalty for this Sunday's Bahrain race.

Webber re-emerged from the pits but lasted one more lap before the lost wheel ended his race - and earned Red Bull a E5000 ($6290) fine.

AAP