Caracas, Nov 27 : Venezuela's Supreme Court has convicted six former American oil executives of corruption and sentenced them to prison. The six Americans, who were executives of US-based refining company Citgo, were arrested in Venezuela on charges of corruption on November 21, 2017, reports Xinhua news agency. On Thursday, the Supreme Court sentenced five of them to eight years and 10 months in prison while one of them received a 13-year sentence. Citgo is owned by Venezuelan state oil company Petroleos de Venezuela (PDVSA). A BBC report on Friday said that the arrested of the six persons marked the beginning of a sweeping anti-corruption operation in Venezuela. Critics of President Nicolas Maduro said the move was part of a political purge. Venezuela's oil industry is key for the government as it accounts for about 95 per cent of the country's export earnings. Last year, the US introduced sanctions against PDVSA after recognising opposition leader Juan Guaido as interim president. /IANS