Fears have been raised that crucial details about Norfolk's heritage could be lost, because of the closure of the archaeological unit which uncovered some of the county's key sites.
Scores of reports by NAU Archaeology, following excavations, have yet to be published, but the unit is being shut down.
Developers had commissioned the unit to carry out excavations ahead of building work and it also worked on the likes of Seahenge and the West Runton Mammoth.
But bosses say it had been struggling to win contracts for a number of years, so is closing.
Staff are being made redundant. Some have already moved to other archaeological companies.
However, Dr Peter Wade-Martins, who helped set up the unit in 1972, fears the closure may mean vital information about excavations is lost - because full reports have not been completed.
He questioned why the unit, originally known as the Norfolk Archaeological Unit and transferred to NPS Group from Norfolk County Council in 2006, needed to be shut, when work was still undone.
Dr Wade-Martins said, when an archaeological contractor completes an excavation for a developer, the contractor is meant to produce a client report and also identify when further publication, in the form of a research report may be necessary.
He says examples of where that has not happened, include:
• An excavation carried on the site of Norwich's former central library, conducted before The Forum was built
• A prehistoric settlement under the Harford Park and Ride site
• Late Saxon town defences discovered during an excavation at Calvert Street in Norwich
• The dig at Norwich Cathedral ahead of the construction of the Hostry
Dr Wade-Martins said closure would be a 'disaster for local archaeology'.
He said: 'On the face of it, it has been successful - winning 60pc of the archaeology contracts in the county, yet it has been obvious that something has been going seriously wrong for several years.
'They started one excavation after another, but seldom seemed to finish them with reports on what they had found.
'I am told from other sources that they have well over 100 unfinished client reports still to complete and there are an untold number of research reports, which we are eager to see, possibly 50 or 60, but they just won't release details.'
Mr Wade-Martins said developer funding should have been sufficient to cover excavation, the preparation and deposition of the project archives and the full cost of writing whatever reports were justified from the results of excavations.
He said: 'NAU Archaeology has produced so few over the last 15 or more years that it should have accumulated a substantial reserve fund by now to pay for all the outstanding post-excavation work. To produce these reports is a professional obligation. '
A spokesman for NPS Group, said they 'did not recognise' the number of uncompleted projects Dr Wade-Martins had quoted.
But they said there were around 30 or so 'live' projects and a 'similar number' of 'historical' projects yet to be completed.
They did not respond to our question seeking confirmation over which projects were unpublished.
The spokesman said: 'It is common in archaeology for publications to take a number of years to produce. For live projects these are in hand and will be resourced to meet Norfolk Historical Environmental Services (NHES) requirements.
'There are a number of very old projects that did not reach publication.
'We are working closely with NHES to tackle this backlog and exploring how we may group together thematically some of the projects to give greater context.
'These days there are now many different methods of publication available than there were in the mid-1990s and we are looking to agree how we can publish these in a contemporary way.
'We are also working with the Norfolk Museums Service to take deposition of our finds and archives which consist of thousands of documents.'
When asked about the money Mr Wade-Martins said should exist to pay for post-excavation work, the NPS Group spokesman said: 'The NAU was transferred by Norfolk County Council to NPS Group in 2006.
'No specific project funds existed nor were passed over, but it was agreed that NPS would take on all of the existing and future obligations.'
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