The project has drawn international criticism, including from Oscar-winning movie director James Cameron of "Avatar" fame, who said indigenous tribes in the Amazon rainforest could turn to violence to block dam construction.

Para state federal judge Carlos Eduardo Castro Martins on Wednesday barred Norte Energia from "building a port, using explosives, installing dikes, building canals and any other infrastructure work that would interfere with the natural flow of the Xingu River, thereby affecting local fish."

The Belo Monte dam is portrayed by Brazil's government as a key piece of its plan to boost national energy production needed for one of the world's fastest-growing emerging economies.

It would be the third biggest dam in the world, after China's Three Gorges construction and the Itaipu dam on the border of Brazil and Paraguay.

The construction ban should be valid from the date that Norte Energia receives notification, likely next week, a federal justice spokesman said.

If the company fails to comply, it would be fined 200,000 reais (about 109,500 dollars) a day, officials said.

Construction that does not affect local fishing, including home building, can continue, the judge also ruled.

The company still may appeal the ruling.

The government had pledged to minimize the environmental and social impact of the dam and asserted that no traditional indigenous land was to be affected.

But in April, the Inter-American Commission on Human Rights (IACHR) asked Brazil to "immediately suspend the licensing process" for the dam, and called on it to protect indigenous peoples in the Xingu River basin whose lives and "physical integrity" would be threatened.

The dam would divert 80 percent of the Xingu River's flow to an artificial reservoir, "potentially leading to the forced displacement of thousands of people," the Amazon Watch non-profit, which fights for indigenous peoples' rights and to protect the environment in the Amazon, says on its website.

But in June, the Brazilian government granted an installation license for the dam, clearing the way for construction to start.

Since he finished working on "Avatar," Cameron has made three trips to the region in the Amazon where the dam is to be built to draw attention to the issue. British pop singer Sting has also given his support to the cause.