Argentina's Supreme Court suspended Friday for 90 days the construction of a dam on the Ayui Grande over fears it could hurt the continent's second-largest wetland.

The Judicial Information Center said the freeze would remain in place ahead of an expected government evaluation of the environmental impact of the dam, due to wetlands near the Ibera Estuary.

Investors in the project include US billionaire George Soros's Adecoagro venture and the Copra group of Jose Aranda, vice president of the media group Clarin, which is mired in a row with President Cristina Kirchner's government over control of the country's only newsprint producer.

Environmentalists warn the dam could destroy vast wetlands. It could also spark a dispute with neighboring Uruguay because the Ayui Grande pours into the Uruguay River.

"The Supreme Court's injunction is a very positive move," Emilio Spataro of the environmentalist group "Salvemos al Ibera" (Save the Ibera) told AFP.

"This ban will have indirect consequences on the Ibera Wetlands because they are in a zone linking the Ibera and the Uruguay River."

Last week, his group gathered 600 protesters in northeastern Corrientes province.

The Ibera wetlands, whose name means "shining water" in Guarani, form a large network of swamps, bogs, lagoons and stagnant lakes stretching across 25,000 kilometers squared (9,650 square miles) in the heart of Corrientes, which borders Uruguay and Brazil.

They are the second-largest wetlands on the continent after Brazil's Pantanal wetland.

Investors insist the dam -- due to be built on the Mirinay River, a tributary of the Uruguay River -- is legal and merely aims to irrigate rice paddies by forming an artificial lake.

In July, Argentina and Uruguay agreed to a joint environmental monitoring program along their shared Uruguay River, ending a seven-year pollution controversy over a Finnish paper mill on the Uruguayan side.