The mystery of whether a North West mountaineer climbed Mount Everest 29 years before Sir Edmund Hilary conquered it could soon be solved.
The mystery of Mallory and Irvine's expedition has endured (Photo: John Noel Photographic Collection)
Four parties are on the mountain trying to find the body of Wirral-born climber Sandy Irvine who perished with George Mallory 80 years ago.
Many Everest experts believe if the pair's camera is found it could reveal if they made it to the summit.
Mallory's body was found on the mountain five years ago.
Four teams of climbers are currently on the peak taking advantage of the most favourable climatic period of the year on Everest
A BBC expedition includes Graham Hoyland, who was part of the team that found Mallory's body.
Irvine's great niece, Julie Summers, from Oxford, said the family are hoping his body and the camera will be found with a photograph showing Mallory on the summit.
But she added, "Even if there are no photographs it is still possible that they made the summit - it is a win, win situation for the family."
Although primitive by modern standards Mallory and Irvine's attempt was considered "high-tech" in its day.
Some of their rivals even complained they were "unsporting" by taking oxygen masks and tanks with them.
"Before he went my great uncle even wrote off to a zip fastener company asking for fasteners," said Julie Summers.
The poignant question of whether the pair made it to the top has endured for 80 years.
They were last seen on 8 June 1924, spotted from below clambering over one of the remaining obstacles of their route.
The summit was only hours away, but they were never seen again.
The first clue to their fate came with the discovery of Mallory's body in 1999, 400 yards off their route.
The pair had obviously fallen together but Irvine's body could not be found.
Neither did the search reveal the camera it is thought that Irvine, a keen photographer, would have taken to the record any triumph.
Photographic experts believe the film would have survived.