The Brighton-born expedition leader who was attacked by a polar bear on Friday has undergone emergency surgery in Norway and been flown back to Britain.
Andy Ruck, 27, is still in a serious condition but stable after being mauled as he tried to protect the youngsters in his care.
He suffered bite and claw injuries to his head in the attack which left one boy, Horatio Chapple, 17, dead.
He was flown first to a hospital on Spitsbergen, an island in the Svalbard archipelago, where the attack took place on Friday (5 August).
He was then transferred to Tromsø University Hospital on the Norwegian mainland before being flown home yesterday (Monday 8 August).
According to one of the Norwegian doctors who treated the survivors, at least two of them may need further operations.
The other survivors were Patrick Flinders, 16, Scott Bennell-Smith, 17, and Mr Ruck’s fellow expedition leader Michael “Spike” Reid, 29.
At least two investigations are taking place into the incident in which five people were attacked, with one dying and four hurt.
Edward Watson, chairman of the British Schools Exploring Society (BSES), which organised the expedition said: “We will leave no stone unturned in investigating the tragic incident on 5 August in Svalbard.
“The Norwegian authorities’ inquiries are under way.
“In parallel we have begun to fully review procedures, examine equipment and gather witness statements to understand if anything could have been done to prevent this tragic incident happening.”
There have been reports that the tripwires set up to protect the camp failed to set off the noisy and bright alarm that would usually be enough to scare off polar bears.
And there were reports that Mr Reid, who killed the bear, had trouble with the gun before eventually managing to fire a round that worked.
Mr Ruck, a travel writer and experienced expedition leader who recently moved to Edinburgh from Aberdeen, was leading a group of 11 youngsters on Spitsbergen with Mr Reid.
He learnt some of his basic outdoor and survival skills during his time as a member of the 42nd Brighton (Saltdean) Scout Troop.
His father Dick devised an animated series of lessons in tying knots and his mother Jan works as a teacher at Saltdean Primary School.
Both parents, from Chichester Drive East in Saltdean, are believed to have travelled to be with their son.