A campaign to prevent 275 flats being built by Pendennis headland due to possible historic buildings buried beneath the surface has received a boost from local planning officers.

In June a local campaigner and history buff discovered that an old bunker was buried beneath the site of Ocean Bowl bowling alley, over which developers are seeking planning permission to build a large student residential complex, to great concern from nearby residents.

Deborah Irvine launched an appeal to prevent developers from building over the site before it had been assessed for archaeological value, but Historic England turned down her proposal on the grounds that there was "a lack of evidence to confirm its original function."

But now her way of thinking has been supported by Cornwall Council's Historic Environment Planning which has stated the belief that the bunker "is potentially a building of national or regional importance."

Historic environment officers have requested that no work is carried out on the site until a full archaeological survey is carried out, and have written in a comment to Cornwall Council: "We therefore consider it essential that a detailed assessment and evaluation of the underground structure should be carried out. We cannot advise further until the appropriate assessment/evaluation report has been provided."

The team also listed four key points for the survey and planning process: That no demolition or development takes place until an investigation scheme has been submitted and approved, nor shall it take place except in accordance with the Written Scheme of Investigation, the site is not to be occupied until the site investigation is complete and the results made public, and the conditions will only be discharged when all elements of the scheme have been completed.

Following the latest development, Deborah said: "Despite it's failure to be listed, Historic England deems it to be significant enough to preserve.

"Hopefully, it will mean that professional archaeologists and historians will be able to solve the mystery of its original use. A few people - including a professional historian and military historian who have looked at the photographs and history of the area - have made educated guesses.

"Its location next to the railway would no doubt be significant and it doesn't look like an air raid shelter, although we do know there were two behind Railway Cottages. As yet, no evidence to prove any of these theories."