Sacha Dench, who was attempting a world-first circumnavigation of mainland Britain in a paraglider to raise awareness about the climate crisis, has been seriously injured in a paramotor accident in the western Highlands of Scotland.

Dan Burton, a member of her support staff, was killed during the incident, which happened late on Saturday afternoon.

Dench is in Aberdeen Royal Infirmary in a serious condition. Nicknamed the “human swan”, she had been attempting a 3,000-mile Round Britain Climate Challenge before the Cop26 conference, due to start on 31 October.

In a statement, the trustees of Conservation Without Borders, which was founded by Dench, said the accident happened near Loch na Gainmhich in the far north of Scotland.

The statement said: “We are very sorry to have to confirm that Dan Burton, the support paramotorist has died as a result of the accident. Sacha Dench is seriously injured and is being treated in hospital. Her injuries are serious but not life-threatening.

“Both highly experienced paramotorists, our thoughts are with the family of Dan Burton, to whom we offer our sincere condolences. The incident was attended by police and medics and inquiries are under way to establish the details of the accident.”

The statement added that the families of those involved had been informed and the Round Britain Climate Challenge would be put on hold.

Police Scotland said officers had been alerted at about 4.45pm on Saturday.

Dench had been flying earlier in the day with Burton, whose role includes documenting the climate challenge from the air, taking film and photographs.

Dench and Burton had landed before taking off again at about 3.30pm. The ground crew, who communicate with the flyers and pick them up when they land, thereafter lost contact.

Dench had begun her climate challenge in June, taking off from Stevenston in North Ayrshire.

Over the following months, she had flown across the UK, most recently over the Kelpies in Falkirk on 3 September.