A Great Britain surfing event was postponed after female competitors – one of them a 15-year-old – were allegedly verbally abused by a group of surfers not involved in the competition.

Semi-finals of the GB Cup were taking place on Sunday at Thurso in Caithness, an area renowned for its surfing conditions, with entrants from Scotland, England, Wales and the Channel Isles.

GB Surfing, the organisation that selects and prepares athletes to compete in the Olympics, said the incident brought its annual competition to an “abrupt end”.

Paul Stark, chief executive of the Scottish Surfing Federation, claimed a small group of surfers had targeted young female competitors with abuse.