Officials in Brazil's largest state are facing mounting pressure to crackdown on illegal gold mining in the Amazon rainforest where thousands of workers are destroying ecologically sensitive land, according to the Amazonas state prosecutor's office.
Since 2007, thousands of miners have descended upon Apui in northwestern Brazil in the so-called "New El Dorado" hoping to strike rich but in the process destroying 14,000 hectares of jungle by cutting down trees and poisoning rivers with mercury.
In a drive to close these illegal mines, prosecutors are now suing Brazil's environment enforcement agency, the Institute of Environment and Renewable Natural Resources (IBAMA), and other government departments which they say have failed to stop ecological crimes in illicit mines.
IBAMA and other government agencies dispute those allegations.
"We want to suspend all (mining) actions on this 14,000 hectares," Amazonas state prosecutor Leonardo Galiano told the Thomson Reuters Foundation in a phone interview.
"We want the government to start campaigns against these environmental crimes."
With Brazil's suffering through its worst recession in a century and high global gold prices, illegal miners have polluted the area with mercury and other chemicals to separate gold from grit while authorities have failed to enforce the law, the prosecutor said.
Mercury, a highly toxic metal, is released into the environment then travels up the food chain to fish, fish-eating mammals and also humans, endangering the health of indigenous people living closest to illegal gold mining operations.
Unsuccessful attempts to stop the mining and lawsuits against other government agencies by prosecutors underline the difficulties in enforcing environmental laws in remote but valuable regions of the world's largest tropical forest.
The prosecutor could not provide a timetable for the lawsuit that could impact illegal mines in an isolated area that is home to about 20,000 people.
Luis Fernandez, a biology professor at Wake Forest University in North Carolina who focuses on the Amazon, said no-one disputed that illegal mining was destroying sensitive forest land but banning the industry is difficult for authorities.
Fernandez said the gold rush had drawn wealthy local businessmen, poor itinerant miners and prostitutes into the jungle - and some workers were victims of human trafficking, living in deplorable conditions.
"Poverty is high and the economy has been destabilized because of Brazil's recession," Fernandez told the Thomson Reuters Foundation.
"In the western Amazon, illegal mining has grown very quickly. It's a major driver of environmental destruction and human trafficking."
Precise data on the value of the black market operations is difficult to find, Fernandez said, but it's likely worth billions of dollars annually.
Prosecutors hope suing IBAMA will force the authorities to take the problem more seriously and launch a new crackdown.
IBAMA spokesman Tiago Costa said the agency brokered a deal in 2010 between the State of Amazonas and gold miners in order to carry out environmental licensing of the mines.
But those licenses were not renewed and the agency has stepped up enforcement activities.
"Recently IBAMA conducted operations ... to stop illegal garimpa (mining) activities," Costa told the Thomson Reuters Foundation by email after the agency sent inspectors into the jungle.
He did not directly respond when asked how IBAMA plans to defend itself from the lawsuit or if more raids are planned.
Prosecutors are considering issuing charges for slavery against pit operators as part of the drive to shutter the mines.
"The aim of this action is to improve conditions for miners who are being exploited," Galliano said.
"What is needed is to regulate and formalize the sector," he said, adding this could lead to better conditions for workers, tax revenue for the government and less environmental damage.