Trudy Harris, AFP - April 20, 2007 16:01 EST

US mining giant Newmont voiced confidence Friday it would win a controversial pollution trial next week, saying claims the company and one of its executives poisoned an Indonesian bay were baseless.

Newmont executive Richard Ness said the prosecution's case against him and the Indonesian unit of the company had been "torn apart" during the 20-month trial closely watched by foreign investors.

An Indonesian court is expected to rule Tuesday on whether Newmont and Ness polluted Buyat Bay in northern Sulawesi with arsenic and mercury from its now defunct gold mine on the island.

They are also accused of sickening villagers and killing marine life around Manado where the mine was sited, around 2,300 kilometres (1,400 miles) northeast of Jakarta.

Ness, who heads PT Newmont Minahasa Raya, the Indonesian subsidiary of the Denver-based company, faces three years in prison if convicted while the company would receive a fine.

"When you look through this whole trial process, starting with the prosecution's witnesses, I think almost every one of them failed to be convincing or their testimony was torn apart by our lawyers," Ness said.

"Our lawyers then systematically proved...that the bay was not polluted, that the water was fine that the fish were fine," he told reporters.

The highly charged case against Newmont, the world's largest gold miner, has pitted environmentalists against mining firms, and the verdict could impact on foreign investment which Indonesia needs to fuel its economy.

Ness reiterated Friday that Newmont, which has been mining in mineral-rich Indonesia for more than a decade, could rethink its operations here if he or the company was found guilty.

"I can't speak for the whole corporation but I can say what our chairman has already stated, he said that anything short of a whole exoneration, they would have to reconsider their position (here)," he said.

Newmont has consistently denied the charges, saying it disposed of toxins safely and that levels of mercury and arsenic found around the mine were well within acceptable levels.

Studies of the waters around Buyat Bay have shown conflicting results. A World Health Organisation-backed report found no evidence of pollution but government tests showed high level of toxins.

Budi Haryanto, an epidemiologist at the University of Indonesia, said a government study he worked on showed arsenic levels in villagers' urine and in their nails could be linked to toxins in their well.

"Results of this study were never formally released to the public," he said.

The Indonesian Center for Environmental Law said it hoped judges would not be swayed by the intense interest in the case.

"We hope the judges will show their independence and make a fair decision based on evidence that has been presented in the court," said Dyah Paramita from the centre.

Ness was also hoping for a "fair and reasonable verdict" from the panel of five judges after three years of legal wrangling over the case.

"Our lawyers have proved that Buyat Bay was not polluted," he said.

"The (prosecution) only had one doctor and she retracted her testimony early on so I don't see there's any evidence left standing," Ness said. "... therefore the allegations are baseless," he said.

Newmont agreed in February last year to spend 30 million dollars in environmental monitoring of the area, as part of an out-of-court settlement in a civil lawsuit with the Indonesian government.

In December 2004 Buyat Bay villagers dropped a multi-million dollar lawsuit against Newmont.