Key Points:

Australian Cabinet ministers 30 years ago approved secret airport transit to New Zealand of a racially segregated South African sporting team three months before helping negotiate a Commonwealth boycott of sporting contact with the apartheid state.

The decision, revealed for the first time in 1977 Australian Cabinet papers, not only overruled the recommendation of Government departments to refuse transit but also required that the decision remain confidential, the Australian newspaper reports.

The Cabinet noted that the South African Ski Boat Angling Team, on its way to compete in New Zealand, "would not be recorded as having entered or departed from Australia".

"The Cabinet further agreed that there be no public announcement of this," the decision, dated March 15, said.

The Australian Prime Minister at the time, Malcolm Fraser, was keen to draw a line between his stance and that taken by his New Zealand counterpart, Robert Muldoon, who had allowed a divisive All Blacks rugby tour to South Africa in 1976.

"We cannot support a New Zealand attitude which we and all other Commonwealth Governments think to be ill-conceived," a Cabinet submission outlining Australia's negotiating position for the June Commonwealth Heads of Government Meeting stated.

But a Cabinet minister who attended the meeting, Ian Sinclair, told the Australian that the Cabinet debate raised legitimate questions of freedom of movement, speech and opinion.

"Why should we interfere in sport, and why should Australia stop New Zealand from inviting a sporting side when [transit through Australia] was the only way those days for a team to travel to New Zealand?" he said.

An interdepartmental committee, consulted on the planned passage through Australia by the six-member South African team en route to a game fishing tournament in New Zealand, concluded that granting transit rights could be seen to offer "support for New Zealand's policy".

It warned that Australia risked losing the right to host sporting events such as the 1982 Commonwealth Games in Brisbane, or to field teams overseas, unless it made its policy on sporting contact with South Africa abundantly clear.

The African nations boycotted the 1976 Olympics in Montreal, Canada, in retaliation for the International Olympic Committee's decision to allow New Zealand to compete despite its Government's decision to allow the All Blacks to tour South Africa.

The Cabinet gave no reason for its decision to allow same-day transit by the South African team, which was not allowed to leave the transit area of the airport. But three months later, Mr Fraser played a leading role in negotiating the Gleneagles Agreement at Chogm in Scotland.

That agreement committed Commonwealth states to "withholding any form of support for, and by taking every practical step to discourage, contact or competition" between their nationals and South Africa.

Mr Fraser told the Australian the debate over the request for transit divided the Cabinet, but he could not recall what led to the decision to grant the permit.

"All I can tell you with accuracy is that there were quite strongly held views on both sides," he said.

Doug Anthony, a Fraser Government minister in the Cabinet meeting, said he did not consider the transit decision a breach of the Gleneagles Agreement.

"I don't think it was a major issue."