Divers retrieving equipment left behind by Mr Shaw found the bodies 20 metres beneath the surface. When the line attached to Mr Dreyer was pulled, both bodies came up. While an autopsy has yet to be completed, the video camera specially designed for the recovery mission, and worn on Mr Shaw's helmet, has provided a record of his last minutes alive.

Boesmansgat Cave, in South Africa's Northern Cape province, is the world's third-deepest freshwater cave. In October, Mr Shaw, 50, a Hong Kong-based pilot, became the only person to have dived 271 metres with the help of rebreather apparatus, which enables divers to recycle air. From the moment he emerged from Boesmansgat Cave, though, Mr Shaw's achievement was overshadowed by his discovery. Even during that first dive, the Australian had tried to recover the remains, still clad in a wetsuit and diving gear. But the gas tanks were embedded in mud. Mr Shaw immediately began planning to bring to the surface the remains of Deon Dreyer, who had drowned on December 17, 1994. Mr Shaw discussed his find with Dreyer's father, Theo. "I promised to do my best to bring him to the surface but reminded him . . . there was no guarantee of success," he said.

With a team of trusted divers, he began planning the operation. A team of eight technical divers and two police divers was to pass Mr Dreyer's body to the surface. On the morning of January 2, Mr Shaw's flight landed in Johannesburg just hours after he had said goodbye to his Melbourne-born wife, Ann, at their Hong Kong home.

Mr Shaw spent the night at the home of Don Shirley, a technical diving instructor. Then they drove to the Mount Carmel game farm of Andries and Debbie Van Zyl, where the cave is situated. For the next two days, Mr Shaw and his team worked in sweltering heat, clambering up and down a 70 metre rocky incline to and from the cave's entrance as they put in place safety measures. While he chatted almost every day to Mr Dreyer's parents - who were on site - Mr Shaw was clear there was no place for emotion. His concern was to get the technical aspects right.

At a private team discussion on Friday night Mr Shaw and Mr Shirley, who would dive the deepest, announced that no one should risk their lives for them. If they died, no one was to try to recover their bodies. It was too dangerous. Just before dinner, Mr Shaw slipped fellow diver Derek Hughes a telephone number for a family friend and Anglican priest, the Reverend Michael Vickers, in Hong Kong, who had agreed to be the bad news contact.

The team of 11 technical divers rose before the sun and drove for 20 minutes along a nine kilometre gravel road to the cave where five police divers, paramedics and a doctor were waiting. At the five-square-metre pool, which is the entrance to the caves below, Mr Shaw pulled on his gear, which included a blue helmet with a video camera on the front to record his mission for a planned documentary. He drank some mineral water, bade his colleagues farewell and began descending to 270 metres. It was 6.15am. At 6.28am, Mr Shirley followed, expecting that Mr Shaw would have cut Mr Dreyer from his tanks, placed his remains in a body bag and started his ascent.

The clear waters revealed only the faintest pinpricks of Mr Shaw's lights and no bubbles to indicate he was on his way up. He was not waving his lights to show he was in trouble. So Mr Shirley continued down to 250 metres to look for him. At around 20 metres from where Shaw's lights were, the computers controlling Mr Shirley's breathing equipment "cracked and imploded". He had to come up to save himself.

About 90 minutes into the operation that was supposed to have yielded a body bag in 80 minutes, support diver Peter Herbst had not found Mr Shirley at the arranged 80 metre mark and he dropped another 40 metres, where he received an ominous message written on a slate: "Dave's not coming back." Just under four hours after the dive had begun, Derek Hughes phoned Mr Vickers, who waited an hour before visiting Mrs Shaw with the news of her husband's death. Mrs Shaw asked that her husband's body not be retrieved, but in the end it surfaced.