Chevron\'s own evidence in an oil contamination case in Ecuador shows the supermajor is engaged in dirty business, environmental advocates claim. An appeals court in Ecuador upheld an $18 billion case against Chevron for oil spilled in the Amazon rainforest. The decision, advocacy groups Amazon Watch and Rainforest Action Network said, is the largest such environmental penalty. Chevron, the advocates said, was found guilty of the deliberate contamination of the Amazon in Ecuador. \"Yesterday\'s ruling, based in large part on Chevron\'s own evidence, once again proves that the company is responsible for deliberately dumping billions of gallons of toxic waste sludge into local streams and rivers, which thousands depend on for drinking, bathing, and fishing, and created a public health crisis in the rainforest region,\" the groups said in a statement. Plaintiffs in Ecuador blame Texaco, which Chevron bought in 2001, for environmental contamination and adverse health effects tied to operations in the country\'s rainforests from 1972-90. Petroecuador, Texaco\'s partner, is to blame for the current pollution, Chevron says. Chevron, in a statement, said the ruling was a \"glaring example\" of the corruption of the Ecuadorian justice system. The company said the case was riddled with fraud. \"Chevron does not believe that the Ecuador ruling is enforceable in any court that observes the rule of law,\" it stated. \"The company will continue to seek to hold accountable the perpetrators of this fraud.\"