A court in east China's Fujian Province has upheld a previous ruling in which the Zijin Mining Group, one of China's biggest gold producers, was fined 30 million yuan (4.62 million U.S. dollars) over a toxic spill last year that caused severe environmental damage, according to a statement issued by the company Wednesday.

The statement said that Zijin received a verdict from the Longyan Municipal Intermediate People's Court, which upheld the previous ruling handed down by the city's Xinluo District Court in January 2011.

According to the court verdict, Chen Jiahong, Zijin's former vice president, Huang Fucai, the company's environmental protection officer and three other company managers were sentenced to jail terms ranging from three years to three and half years.

Some of these sentenced received probation, but the company statement did not say who received the probation.

A wastewater leak containing acidic copper from the company's Zijinshan gold and copper mine spilled into the Tingjiang River last July and killed or sickened thousands of fish, causing direct economic losses of more than 31 million yuan.

A follow-up investigation showed that the leak occurred because of poor maintenance of the plant's tanks, including one sewage tank.