Two British teenagers fell 400ft to their deaths after a parasailing accident while on holiday in Greece when the rope on their speedboat snapped, it has been reported.

A boy, 13, and a girl, 15, both cousins, tragically died while another, the boy’s 15-year-old brother, is fighting for his life in hospital in Rhodes.

They were being towed by the speedboat when a rope holding their parasailing parachute snapped, the Greek coastguard said.

The trio fell from an “extreme” height and crashed into rocks in high winds.

Horrifying pictures from the scene showed authorities recovering the bodies.

An investigation is ongoing but eyewitness accounts say the teenagers had fallen onto the rocks from an altitude of about 400ft, according to the Daily Mail.

The trio fell from an 'extreme' height and crashed into rocks in high winds [stock photo]

The usual safety limit on most Greek islands is 300ft.

The surviving boy is in a "serious condition with multiple injuries" in hospital and is fighting for his life in a coma, according to local media.

The trio are said to have been found on rocks near Lindos on the island of Rhodes.

Local media said the victims were killed instantly when they hit the rocks – while the 15-year-old boy was found injured.

Local media said the victims were killed instantly when they hit the rocks while a boy, 15, is fighting for his life [stock photo]

It happened on Wednesday at about noon local time and two people connected with the speedboat have been arrested.

The Greek coastguard spokesman said: "They were following a speedboat. The rope was cut.

"The boy and the girl were killed and another was heavily injured and brought to hospital.

"It is under investigation about how the rope was cut."

Local media reports that three or more people parasailing from one glider is prohibited.

Lindos Bay in Rhodes Island, Greece [stock photo]

The bodies of the teenagers were found by members of the coastguard and the fire department who had been contacted by the person who controlled the boat, according to the spokesman.

He said: "The guy who controlled the speedboat and another person were arrested."

High winds had caused the group to drift towards the rocks, Greek media reported.

Τhe siblings and their cousin had arrived to the island  with their family a few days ago and were staying in Pefki resort.

The Foreign, Commonwealth & Development Office (FCDO) confirmed it had been liaising with the family of the teenagers.

A FCDO spokesman said: "We are supporting the family of two British people following their death in Rhodes, and are in contact with the Greek authorities."