Less than a fortnight later, Crossing would hand over the cheque to buy the most controversial painting in Australian history, Jackson Pollock's Blue Poles.

When Crossing got the call, the then-acting director of the Australian National Gallery, James Mollison, and senior assistant crown solicitor Wilfred Frey, were flying in to negotiate the sale. Crossing, deputy consul-general (financial), was to help.

Two months before, Prime Minister Gough Whitlam, acting on the advice of the gallery's acquisitions committee, had approved the purchase. "Buy it," wrote Whitlam on the brief from his department in July, "and disclose the price."

News of the purchase had made the front page of the Financial Review in August. "The story was that we had already paid a deposit on Blue Poles," Crossing, now 99, says.

"We were asked to pay, I think it was $20,000 US. We paid a deposit on it. I hadn't seen it at that stage, didn't even know what it was. We were buying other artworks for the gallery that was to be."

Crossing met Mollison and Frey at the Gotham Hotel in New York on Sunday, September 16, discussing the price, the payment terms and delivery. Notes kept by Frey, now in the National Archives, record the negotiation process.

On Monday, the three men visited Ben Heller, the textile magnate and prominent art dealer selling the work.

"Ben Heller invited us to come in to have dinner with him. Very gracious, I thought. We went along and I saw the painting for the first time and was a bit surprised. It was a very impressive object there. There was not much done that evening. We did talk about it and the conditions," Crossing says.

Heller's Central Park West apartment at the time was filled with landmark pieces of modern art. Blue Poles - more than two metres high and nearly five metres across - loomed large over the negotiations.

"Blue Poles was on this partition, and the other end of the huge room, that looked like a museum room, was a Rothko, a very great work of art too. There were artefacts all around the room. It was just an amazing sort of place," Crossing says.

Mollison, who had been looking for a Pollock for the national collection, was eager to get the sale. Max Hutchinson, whose New York gallery was the agent for Blue Poles, cabled Mollison on June 6 to say the perfect painting was available. Years before, Mollison had worked for Hutchinson in Australia.

"Blue Poles available at two million US dollars with painting retained in USA for one year. Painting is magnificent, condition same," the cable said.

Less than six weeks later, Whitlam had agreed to buy it, even if Heller wanted to hang on to the painting for another year.

That condition concerned Crossing, who set to work with Frey in drafting tough conditions. Both men wanted to take delivery of the painting straight away.

"I was worried about it because, as I said, it had bad publicity in Australia. The articles saying that it was a horrendous price to pay for a piece of artwork. There was ignorant criticism of it. So I got together with the crown solicitor man, Wilfred Frey, and we started writing contracts requiring the protection of the painting and so forth. We were making these pretty tough," Crossing says.

At 3pm on Thursday, September 20, the Australian negotiators - Mollison, Frey and Crossing - were joined by American art lawyer Gilbert Edelson at a second meeting in Heller's apartment.

"The meeting was an intense and at times emotional one, mainly due to the attitude of Mr Heller that he was unable to accept the responsibilities and restraints the agreement would place on him during his retention of the painting and his subsequent delivery of it," Frey wrote in a file note later that year.

Crossing says Heller had the air of a man who knew the work he was handling. "He wasn't aggressive. He was fairly polite, but he knew his stuff. You could tell from the way he spoke. Of course, as you know, he died recently. It was a tough negotiating experience and I don't think we got any kudos for bringing it off.

"At the time Blue Poles was bought, the attitude in Australia was pretty negative. I'd say the Australian people were not happy. There were articles - you know, 'Drunks did it' and so forth - that denigrated the work. I think they were just people, the sort who say there's no climate change."

Mollison, however, was "deadly eager" but sat back and let the negotiations happen, Crossing says. "He didn't care what happened, so long as he got the work. His whole attitude was he'd agree with anything to get the work. He spoke about it as something he'd really like to achieve to get that work for the gallery."

Not long after the meeting, Heller rang Mollison. He would sell the painting outright. "Eventually Heller gave in and said, 'Oh, I might as well let it go.' And that was what we were after," Crossing says. "All seems rather simple now, but it wasn't at the time."

Crossing says the negotiators were bent on getting the best terms they could. When Heller said it could go immediately, the three knew immediately they had done it. "So we had a few policeman with us and we put them on guard duty to mind it."

Less than a week later, Crossing sent a cable to say the payment had been settled. He had handed over the cheque, paying $1.3 million and setting a record price for an American painting.

Australia owned a Pollock, which would be brought from the US onboard a Australian Navy aircraft carrier. It would first go on show in Sydney in April 1974.

"The picture gets more fabulous the more you look at it," Crossing says. "This was my thought when I saw it: I'm glad I didn't have to make the decision whether to buy it. I wasn't so sure that I would want to pay $1.3 million for it. That was the first thing. I liked it, but I was pleased the decision had been made for me."

Mollison, who died in January, had a different view. "Blue Poles," he told The Age a year after it was bought, "is too sweet for my taste. I prefer pictures that are harder to come to terms with."

Current National Gallery director Nick Mitzevich disagrees with Mollison. He also says the painting has had an amazing life. "This picture is one of the most important in the latter part of the 20th century because Pollock changed what art was about."

Crossing says when he sees the painting now, he sometimes has an urge to tell the guard he was the one who bought it. "They would think I'm crazy," he says.