Organisers of a luxury ultramarathon have apologised after leaving yellow markings on an Arran mountain.

Highland Kings said work to remove the marks on Goatfell, made with biodegradable chalk, was now complete.

An ascent of the mountain formed part of day four of the event, which cost competitors more than £15,000 to enter.

Landowners National Trust for Scotland (NTS) said it had been assured there would be no signage and was "very disappointed" markers had been used.

Goatfell is Arran's highest mountain and is part of land on the island owned by the trust.

Local mountaineers and walkers have been outraged to find dozens of the markers drawn onto rocks on many routes. 

They warned that as well as being unsightly, the arrows and dots could confuse hikers into taking dangerous paths, or choosing the wrong route. 

An NTS spokesman said: "We were very disappointed given that we had made prior contact with the organisers and had asked them not to use signs or drones on the hill and were told that there would be no signage at all but people marshals only.

"We made it clear to them that we expect all events on Trust land to be operated on a 'leave no trace' basis."

The NTS said it had made contact with event organisers via its solicitor after the navigation markers were discovered last week.

Rangers are expected to check that all signs have been removed over the next few days.

HeraldScotland:

Goatfell is protected by the National Trust

The Highland Kings event involved 120 miles (193km) of trail running on Scotland's west coast and included transfers by speedboats to luxury accommodation at the end of each day.

A spokesperson said the company was "acutely conscious" of the environmental impact that races like this could have and would "learn from this experience".

"We sincerely apologise for the upset we have caused in relation to route markers on our recent ultramarathon event," the statement added.

"It was always in our operations plan to have our team return to the route in the days following the event to remove all trace of the biodegradable chalk.

"All materials during the event were specifically selected to protect our green spaces including the use of biodegradable chalk."