An international tribunal has sided with Chevron and ruled that the government of Ecuador violated international law in obtaining a $9.5 billion judgment against the US supermajor.

Chevron said Friday the tribunal had unanimously determined that the award was "procured through fraud, bribery and corruption and was based on claims that had been already settled and released by the Republic of Ecuador years earlier".

The case stems from accusations by Ecuadorian villagers that Texaco, which Chevron purchased in 2001, had polluted the environment in 1964 and 1992.