UNDERWATER archeologists are hoping the secrets of Suffolk's lost city are not buried forever.

Mapping the medieval city of Dunwich has become a lifelong labour of love for aquatic explorers and local historians – but a layer of silt threatens to curtail cartography until funding can be found for the required technology.

Stuart Bacon, marine archaeologist and director of the Orford-based Suffolk Underwater Studies, said: 'We have found the ruins of churches less than a quarter of a mile from shore. But the further out we go, the deeper the layer of sand that needs penetrating.'

Just two days of 'sub-bottom profiling' cost �25,000, of which �20,000 was raised through a donation from the Esmee Fairbairn Foundation.

But Mr Bacon fears future funding will be difficult to obtain. 'We hope to learn more about Dunwich but its not easy to get support without any monetary value at the end. The secrets of Dunwich may remain secrets,' he said.

Dunwich was the capital of East Anglia 1,500 years ago. In 1286 a sea surge hit the coast and it was reduced through coastal erosion to the village it is today.

It is believed there are 16 major structures underwater, including churches, chapels and monasteries.

Expedition leader, Professor David Sear, of the University of Southampton, said many of the city's lost buildings are yet to be discovered, but rates of sand deposition are accelerating and many remains lie buried.

'Special technology does exist but it's relatively expensive,' said Prof Sear. 'It's just a matter of funding but I'm optimistic.

'It could tell us quite a bit about how our coastline eroded.'

The team are currently trying to raise money to continue the work.