Kathleen Mitchinson, Charlotte Allin and James Manning, along with two other divers believed to be from France and Sweden, have now been missing for more than 24 hours.

The alarm was raised after the group failed to return following a dive off the remote Komodo National Park in Indonesia, on Thursday.

The diving expedition was organised by the Reefseekers diving centre and led by British dive master Mrs Mitchinson, CNN reported.

It is thought six people wearing snorkelling equipment returned but the divers did not.

The waters off the isolated park are attractive to divers but the area boasts strong and unpredictable currents which can create challenging conditions.

Police and rescue teams were summoned after an initial search proved fruitless.

A Foreign Office spokesman said police and local authorities had been searching the area.

The next of kin of the missing divers have been informed.

Komodo National Park is situated more than 200 miles east for the nearest city, the Bali island capital of Denpasar.