Christian Horner has rubbished suggestions Daniel Ricciardo could join Ferrari by insisting the Australian has a watertight contract at Red Bull for 2016.

Ricciardo is one of the names which has been linked with Kimi Raikkonen's seat should Ferrari opt against retaining the Finn's services next year, though Valtteri Bottas remains the favourite. When asked about the rumours in June Ricciardo refused to rule out the move and said he did not know the intricacies of his Red Bull contract, which has three years left to run.

However in Hungary Ricciardo admitted there had been no contact from Ferrari in the three weeks since the British Grand Prix as rumours about Bottas intensified. Horner has played down the Ricciardo link further by emphasising the strength of his contract.

Asked whether Ricciardo's contract for 2016 was "watertight", Horner replied: "Absolutely."

The follow up question was whether the Ferrari stories had any foundation, to which the Red Bull boss simply said: "No, none at all."

Ricciardo scored his first podium of the season in Hungary, though his chances of victory slipped away in the closing stages following contact with Nico Rosberg. Horner , who has already said Ricciardo's "half-term report is A+" going into the summer break, thinks the Australian back to his best again after a mixed start to the year.

"You can always improve in some areas, of course you can. But he's at the top of his game and some of his overtaking moves [in Hungary] were back of the best that we've seen of him."