A new exhibition at the British Museum will showcase treasures from the underwater archaeological discoveries in Egypt next year. The exhibition will put on show, for the first time in Britain, artefacts recovered from the sunken ancient Egyptian cities of Thonis-Heracleion and Canopus, the museum announced.

The lost neighbouring cities were discovered by archaeologist Franck Goddio and his team from the European Institute of Underwater Archaeology (IEASM) in 2000. Both the cities were located near Alexandria and are believed to have sunk in 2 or 3BC. Submerged under 10m of water, the ruins are located in the ancient harbour of Alexandria and Aboukir Bay on the Mediterranean Sea in Egypt.

Thonis-Heracleion was named after the Greek hero Heracles and has its principal temple dedicated to Heracles. The city had a thriving Greek community centuries before Alexander the Great arrived in Egypt. Its location at the mouth of the Nile made Thonis-Heracleion an important centre for maritime trade in ancient Egypt, Goddio wrote in his research paper.

Canopus was a major centre for the worship of the Egyptian god Osiris. Osiris was brought in his ceremonial boat during the annual procession from a temple in Heracleion to his shrine in Canopus. "A mystical connection thus linked the two neighbouring cities through the worship of Osiris," he wrote. Devotion to the god would ensure continuity of the dynasties.

Exhibits from the ruins of the two submerged cities will feature a range of objects that were well-preserved under the sea for more than 1,000 years. These include magnificent colossal statues, intricate gold jewellery, sacred offerings and ritual objects.

The exhibits "tell stories of political power and popular belief, myth and migration, gods and kings", the museum said in a statement, adding that the ancient cities show deep connections between the great ancient civilisations of Egypt and Greece.

The exhibition will be held from 19 May to 27 November in 2016.