A British tourist has died while snorkelling off a popular Indonesian island.

The 81-year-old was found “floating lifeless” about 15ft from the coast of the tourist island of Gili Trawangan, northwest of Lombok, on Wednesday.

A preliminary medical examination suggested the man suffered a heart attack while in the water, police said. The cause of death has not yet been confirmed.

The tourist was on a group boat trip to the snorkelling spot when he became separated before later being found, according to police and witnesses.

“After arriving at a spot off the Wah Resort, the tourists dived at the location only five metres from the shoreline. They were there for around 10 minutes when the victim was discovered floating motionless in the waters,” Gili islands police chief Iptu Mahardika said.

The tourist was swiftly brought ashore for emergency attention, but was pronounced dead after a medical examination, according to News of Indonesia.

Authorities contacted the British Embassy in Indonesia to pass on the tragic news to the tourist’s family.

“We are supporting the family of a British man who died in Indonesia and are in touch with the local authorities,” a Foreign, Commonwealth and Development Office (FCDO) spokesperson told The Independent.

The island is well known for its beaches and sunset views, with tourists visiting to enjoy the landscapes, bars and restaurants.