Renato Brill de Goes, the federal prosecutor who is acting on behalf of dam opponents, questioned why the dam was put back on track so quickly, just a day after the suspensions were appealed by the government.
He said that an appeal would be filed against this decision.
James Cameron, the Avatar director, who recently spent a week in Brazil protesting against the dam, asserted that government pressure played a role in the quick court reversal.
"The justice system in Brazil has succumbed to government pressure and justice was not served in this case," he told Al Jazeera.
"The battle is not over and, in any event, we made news while we were."
The original decision halting the dam from going forward had come on Wednesday, when Cameron was visiting a small city near the proposed dam site.
Aneel, Brazil's electricity regulator, resumed plans to hold an auction on Tuesday to choose a consortium.
The consortium that offers the lowest price for producing electricity will build the $11bn dam and sell electricity to the nation.
Battle not over
Amazon Watch, a San Francisco-based group that works to protect the rain forest and the indigenous people living there, pledged on Friday to continue backing the anti-dam campaign.
"We are committed to supporting Brazilian indigenous peoples who have vowed to fight to stop the Belo Monte dam," the group said.
Amazon Watch members accompanied Cameron on his Brazil visit and said that "the battle is not over.
"This dam is one of the most destructive projects ever undertaken in the Amazon".
Belo Monte would be the world's third-largest hydroelectric energy producer, behind China's Three Gorges dam and the Itaipu dam that straddles the border of Brazil and Paraguay.
Environmentalists and indigenous groups say Belo Monte would devastate wildlife and the livelihoods of 40,000 people who live in the area to be flooded.
They also argue that the energy generated by the dam will largely go to big mining operations, instead of benefiting most Brazilians.
Luiz Inacio Lula da Silva, the Brazilian president, has repeatedly insisted that the dam is essential, and says it will provide clean and renewable energy to feed increasing demand.
Latin America's largest nation has a fragile energy grid that was hit last year by a blackout that darkened much of the nation.
Belo Monte would supply six per cent of the country's electricity needs by 2014, the same year Brazil will host soccer's World Cup and just two years before Rio de Janeiro holds the 2016 Olympics.
Lula has suggested that foreigners should not tell Brazil what to do in the Amazon.
But Cameron said the nation's jungle is an international issue because the Brazilian Amazon is seen by many as the world's biggest natural defence against global warming.
It acts as a "sink", or absorber, of carbon dioxide while also serving as a contributor because about 75 per cent of Brazil's emissions come from rain-forest clearing, as vegetation burns and felled trees rot.
"I am sure (Silva) doesn't like us poking around in his affairs, but this is an international issue," Cameron said.
"The international community needs to engage on this issue because it affects all of us."
Cameron said he believes his opposition to the dam will give opponents a boost because his presence has focused media attention on the issue.
"The tug of war has become quite public in the media in Brazil and internationally, and that's a gain because up until now the people affected by the dam haven't had a voice," he said.
Sigourney Weaver, actress who starred in Avatar, accompanied Cameron to the jungle city of Altamira and to Brasilia for a protest march.
Their visit was reminiscent of a 1989 trip by the rock star Sting, who protested against the same dam alongside Indians in an event that helped persuade international lenders not to finance it.
Brazil was reeling under a heavy foreign debt at the time.
But an economically booming Brazil no longer needs money from abroad now to build the dam.