Hamilton, Formula One's first black driver, was booed and insulted by spectators, some wearing wigs with blackened faces, who shouted racial abuse during testing at the Montmelo circuit in Barcelona in February.

The incident provoked outrage and calls for action, with some commentators suggesting Barcelona could be removed from the calendar if there was any repeat.

On Thursday the FIA, Formula One's governing body, launched its EveryRace campaign against racism ahead of the Spanish Grand Prix, and Hamilton provided his endorsement.

"I believe that motor sport, like all other sports, is about freedom of expression in the pursuit of competition and excellence. Nothing more, nothing less," Hamilton said.

He was joined by a host of drivers and FIA president, Max Mosley, who is currently fighting allegations in a UK tabloid newspaper that he took part in an orgy with Nazi overtones.

Mosley reiterated comments he has made in the past about why he got involved in the sport.

"One thing that most attracted me to motor sport was that nobody cared about your background, race, gender or religion; all that mattered was how quick you were."

Formula One supremo Bernie Ecclestone echoed Mosley's thoughts, saying: "The sport is all about a driver's ability and this will never have anything to do with their race or the color of their skin."

Reigning world champion Kimi Raikkonen said "prejudice" had no place in the sport, while his Ferrari team-mate Felipe Massa believed F1 should "promote equality wherever we can."

Meanwhile, the FIA said in a statement that it was happy with the response of Spanish officials to the situation and agreed with the RFEA (the Spanish motor sport body) that a very small number of the 35,000 spectators at the February testing session were involved.

"The FIA agrees with the RFEA assessment that the people involved in these incidents were 'not at all representative of the thousands of people who enjoy a convivial atmosphere and the spectacle offered by motor sport.'"

The FIA said there had been no further incidents.