A POLAR bear that mauled a Bishopstone schoolboy to death had worn-down teeth and gum disease which would have made it stressed and behave “aggressively and unpredictably”, an inquest heard.

Horatio Chapple, 17, was on an expedition to the Svalbard islands in August 2011 with the British Schools Exploring Society (BSES) when he died.

He and two friends woke to the polar bear shaking their tent and Horatio subsequently suffered fatal injuries to his head and upper body.

His two friends, Patrick Flinders, 17, and Scott Bennell-Smith, 16, were also injured as well as leaders Michael Reid, 29, and Andrew Ruck, 27, before the animal was shot dead by Mr Reid.

A Norwegian police report read out at the inquest at Salisbury Coroner’s Court today said the bear was most likely about 24 years old.

A post-mortem examination showed the animal had worn-down teeth, a cavity and inflammation of the gums.

The inquest heard the pain the bear was suffering would have “affected its ability to obtain food” and influenced its behaviour significantly.

“It was most likely the pain raised the level of stress, causing it to react more aggressively that it would have done without pain,” the report said.

Today the inquest also heard from Lieutenant General Peter Pearson, executive director of the British Exploring Society, and Edward Watson, chairman of the society.

Both said the society has changed its policy in light of the incident following an independent inquiry carried out by former High Court judge Sir David Steel.

The court heard that it was only discovered that vital pieces of equipment used to make a trip wire alarm system around the groups’ camps were missing from the expedition’s supplies when they arrived at base camp.

Each group only had three mines instead of four and didn’t have enough supporting stakes to hold the wire and there was a shortage of firing mechanisms.

Horatio’s group made modifications to the trip wire system, which expedition leader Michael Reid said were 100 per cent successful when they tested it but the cartridge failed to fire when the polar bear charged the camp.

The inquest is expected to conclude tomorrow.