London: Red Bull team principal Christian Horne has accused Mercedes of pursuing `underhand` tactics, after it was disclosed that the latter had taken part in a secret advantageous three-day Pirelli tyre test well before the Monte Carlo Grand Prix.
Mercedes, however, denied claims that Nico Rosberg`s win at the Grand Prix was a result of the tyre test.
The German team is likely to face a potential cheat ban in the wake of protests by Red Bull and Ferrari.
Horner described as wrong that another team, had in an underhand way, consciously tested tyres that are designed for this year`s championship despite the testing rules being very clear, adding that it is a contravention of not only the Monaco race, but of the overall championship.
Horner also predicted that the entire testing operation would have cost over a million pound.
The word did not leak out until the test was mentioned at a drivers Grand Prix Drivers` association (GPDA) meeting in Monte Carlo a week later.
Hamilton, who finished fourth in the eventful race, however insisted that the team had not done anything wrong, adding that he slowed down a lot.
He later apologized to the team and said that he felt that he was not good enough this weekend due to which he lost many points.
According to a report, Mercedes carried out the test after the last round in Barcelona, where both Hamilton and winner Rosberg were involved.
Mercedes executive director Toto Wolff defended his team by saying that what they did was exactly according to the rules as it was a test conducted by Pirelli.