The Greens say they are puzzled as to why the Federal Government tried to claim it had not seen an anthropological study for a region that is the likely site for a proposed national nuclear waste dump.

Minister Kim Carr yesterday admitted that the Resources Minister Martin Ferguson's office had the Northern Land Council conducted on the area around Muckaty Station, near Tennant Creek.

But he said it could not be released in full because it contained sensitive cultural information.

West Australian Greens Senator, Scott Ludlum said the Government may have simply lost the study.

The key to the thing is though that it's the most important document," Mr Ludlum said.

"The Government's entire case rests on it, so it's bizarre in the least for them to claim that they have not seen it and were not in possession of it.

"I think that is extremely troubling just in itself."

The Federal Resources Minister Martin Ferguson has accused the Greens of not respecting the rights of traditional owners in the Northern Territory.

Mr Ferguson says the Greens' demands to reveal details of the study would violate the confidentiality of traditional owners who have agreed to the dump being on their land.

"This morning they are out in the media attacking the views of Wilson Tuckey, the member for O'Connor, for not having respect for indigenous rights," Mr Ferguson said.

"At the same time, they want to play an alternative card in the Northern Territory, questioning the operation of the Aboriginal Land Rights Act."

Mr Ferguson has conceded that building a nuclear waste dump in the Territory may cause problems for Lingiari M-P Warren Snowdon at the next election.

He said it was a difficult issue.

"As you make tough decisions there are always going to be some aggrieved persons," Mr Ferguson said.

"But a process started in 1988 cannot go beyond this Parliament, because we have to establish in accordance with the international protocols a repository which meets our needs domestically and meets out international commitments."