Doubts linger over the effectiveness of the $108 million clean-up of the Maralinga nuclear test site, despite Federal Government claims that it was a success.

A former head of the Federal Government's Maralinga Rehabilitation Committee (MRC) says the clean-up of the South Australian nuclear test site has not been successful.

The former head of the MRC, nuclear scientist Alan Parkinson, says the shallow burial of nuclear waste at Maralinga is dangerous and a failure.

He says all of the material should have been treated using in-situ vitrification where the material is virtually melted on-site, but the Government stopped that process after an explosion in 1999.

"The Government used that as an excuse to cancel the remaining vitrification and simply buried everything, in a totally unsuitable geology in an unlined trench - in that respect, the project was an abject failure," Mr Parkinson said.

"The Government's own documents pertaining to the national store for radioactive waste says that shallow burial of long-lived isotopes is not acceptable, but that's exactly what happened at Maralinga."

But a legal adviser to the Maralinga Aboriginal Community, Andrew Collett, says he is satisfied the clean-up has been and trusts the Government's declaration the site is safe.

He says the process of returning the land to the traditional owners will continue.

"The negotiations are underway with the current negotiation of a land management agreement to deal with who monitors the land in the future, who looks after it and what should happen if any further contamination is discovered," Mr Collett said.

"Maralinga Tjarutja has at all stages had access to all of the Australian, American, and British scientists involved in the clean-up, but more importantly Maralinga Tjarutja has always had unlimited access to its own independent scientific advisers who have advised that the clean-up is the best that could be achieved."