The 28 artworks were to have formed the gallery's major winter show Ngura Pulka – Epic Country.
But an article published in The Australian newspaper in April alleged paintings by Anangu Pitjantjatjara Yankunytjatjara (APY) artists had been interfered with by non-Indigenous art workers.
The allegations shook the Aboriginal art industry and the exhibition was postponed indefinitely while the National Gallery launched a review by intellectual property law experts, barrister Colin Golvan and lawyer Shane Simpson.
They have found the artists exercised "effective creative control" over their work, and the paintings comply with the National Gallery's provenance policy.
Their findings state the word of the artist is of "utmost importance" in determining attribution, and each artist involved said the work was their own without hesitation.
"Without exception, the artists to whom we spoke unequivocally told us that the works under review in each case were made by them and expressly denied that there had been any improper interference in the making of their work," the review stated.
The review quoted several comments from artists, such as: "That is my painting; that is my work"; "It was only us Anungu people"; "No one added to it. It's from our hands, the family did this together".
The National Gallery said it accepts the findings and has agreed to reschedule the Ngura Pulka exhibition.
The initial interference allegations centred on the APY Art Centre Collective, but the review noted a broad examination of the centre was outside its scope.
For its part, the collective has welcomed the findings.
"The attack on our integrity and our art has been rejected and thrown into the rubbish bin where it belongs," it said in a statement signed by dozens of its artists.
APY Art Centre Collective general manager Skye O'Meara said the allegations were part of a deliberate effort.
"The attack on the integrity of the artists and their work, which has been debunked today, was an opening shot in a deliberate effort to destroy the Collective and its significant artistic, cultural and economic achievements," she said.
The National Gallery says it will monitor a South Australian government review into the APY Art Centre Collective which is ongoing.