Fresh evidence about a mystery shipwreck has prompted archaeologists to apply for a government licence to carry out further investigations.

The collier ship, which dates back to the 18th or early 19th century, has been exposed for the third time in recent years off the coast of Seaton Carew, near Hartlepool.

Archaeologists have battled against time and tide to try and find out more over the few weeks it was exposed.

Historians recently discovered fresh evidence when an old photograph of the wrecked brig, built in a style similar to Captain Cook's HMS Endeavour, was unearthed by local historian Maureen Anderson.

The 1898 photograph was taken by a priest after which the collier ship then disappeared beneath the waves again until 1996.

It re-emerged briefly in 2002 and part of the vessel became exposed in the last few weeks but it has become almost submerged once again.

Gary Green, marine archaeologist at Tees Archaeology, explained that it was first spotted by an elderly gentleman who had been walking Seaton Carew beach for more than 70 years.

"He had never seen anything like it in all that time," said Mr Green. "We've been left trying to find out as much as we possibly can about it. The trouble is there are hundreds or probably thousands of wrecks off our coast. Trying to go through the records to find evidence of it would be like trying to find out about a single piece of scrap in a 200-year-old scrapyard."

Mr Green explained that, although the collier brig was a common vessel, it was an important find.

He said: "It was a common vessel but we have very few existing examples of that kind of ship. The 19th Century picture shows that the vessel was stripped off everything they could salvage from it, right down to the planking."

Wood samples have been taken for tests from the largely oak ship but did not accurately date the vessel. It is thought changes in the weather conditions have led to the collier becoming exposed more regularly.

Mr Green said re-floating the 80ft and 20ft wide ship, like the Mary Rose in the 1980s, would cost millions of pounds and would be out of the question.

Anyone who may have information on the wreck can call Tees Archaeology on (01429) 523455.