(bbc) - Brazil's Congress is to be asked to consider a law which could require foreign visitors and workers in the Amazon region to have a permit.
The legislation is designed to prevent outside interference and illegal use of the rainforest's resources.
Those in the region without a permit would be fined up to $60,000 (£30,000).
But some scientists have warned that if passed the measure could have a negative impact on research, and would force experts to look elsewhere.
There has long been a suspicion in some sections of Brazilian society that not all the attention focused on the Amazon region is well motivated.
Brazil's National Justice Secretary Romeu Tuma now says a bill is to be sent to Congress requiring foreign visitors and workers in the area to have a permit.
In an interview with the Associated Press news agency, Mr Tuma said Brazil wanted the world to visit the Amazon.
But he also said they wanted visitors to inform the government when they are coming, and what they were planning to do while they were there.
"We want to establish the Amazon as ours," he said.
In recent years the Brazilian government has become increasingly fearful of what it views as bio-piracy, or the appropriation of traditional or indigenous knowledge and biological resources, in what is the world's largest remaining rainforest.
The Brazilian government insists that it is not trying to criminalise foreigners visiting or working in the region, but simply trying to distinguish between the good and the bad.
The proposals would require overseas organisations, including religious groups and individuals, to seek authorisation to be in the area from both the justice and defence ministries.