Mercedes released an open letter to fans on Wednesday in which they dismissed social media claims that the German team are deliberately favouring Nico Rosberg over world champion Lewis Hamilton.

While Rosberg has won the first four races of the season, Hamilton has been bedevilled by mechanical problems and currently lies 43 points behind his German team-mate in second place in the drivers' championship.

Team boss Toto Wolff said after Sunday's Russian Grand Prix in Sochi that the conspiracy theorists were a "bunch of lunatics lying in their beds with their laptops on their chests".

And in a 1,100-word letter published on their website, Mercedes said: "To paraphrase Mr Toto Wolff, we have worked our a**es off to get where we are today -- and we have done so as a team.

"We have the best guys and girls in the world, doing an awesome job, week in and week out -- and they do it for the team. Not for one driver or the other -- but for each other. There is no 'A' or 'B' team here."

The Britain-based team added: "To those who stand with us, we thank you. And to the rest -- the haters, the naysayers, the conspirators... if we can convince even half of you of what we really stand for, we'll consider that a battle well won."

Hamilton and Rosberg have swapped mechanics this season, but Hamilton said at the weekend that there is nothing suspicious about that.

"We swapped for no apparent reason, but that is not the reason we're having issues," said the Briton, who is chasing a third consecutive world championship and fourth in total.

"Don't jump the gun. It's (favouritism) not happened in the last three years and I have no reason to think that it's happening now." afp