An internal inquiry is under way at Teignbridge Council after the original 1998 planning application document for the Combined Linen Service laundry, at Decoy, Newton Abbot, mysteriously vanished.

Police have been alerted and the district authority has carried out a search of its Forde House headquarters, but has so far drawn a blank.

David Beer, assistant to the chief executive, confirmed that it was discovered the document was missing on Tuesday last week, only hours before a heated public meeting into the laundry development.

He said the disappearance had been reported to police, though as yet an investigation had not been called for.

'We've never had a situation like this,' said Mr Beer, 'and we felt that we ought to log the disappearance with the police as a precaution.

'We have conducted a full internal search but so far we cannot trace the planning application.'

The document formed part of the evidence considered by the ombudsman in his recent investigation which found the council guilty on two counts of maladministration regarding the laundry's development.

It is unclear when the planning application was removed from its file.

The disappearance is a mystery, as the paper has been in the public domain since it was originally lodged and contains no confidential information. Mr Beer also confirmed that its loss – there is no duplicate – would have no bearing on the CLS development or any future plans the company might submit.

Historically, anyone wishing to view planning documents had simply to turn up at the department's reception at Forde House and request that the file be produced.

No record of the request was kept and no formal checks were made to ensure it was returned in its entirety.

The lost document comes as no surprise to chairman of the Aller Park Residents Action Group, Brian Yates.

'Members of the group have visited the planning department on several occasions to view documents relating to the laundry development and frequently sections were missing.

'When we enquired as to their whereabouts nobody knew and we were simply told that someone was working on them. There is no system in place for recording who has them and as recently as Wednesday of last week – the day after the public meeting – I went to look at the papers and the situation was exactly the same then.'

Christian Barnett, spokesman for the planning department, said that the procedure for viewing documents had now changed and anyone wishing to view records had to provide 24 hours' notice.

As part of an investigation into planning applications, this reporter requested files for inspection on Tuesday which were duly produced on Wednesday.

They were handed over without the need for a signature or identity check and the documents were allowed out of the sight of staff. On returning the file, no check was made to ensure that the paperwork was returned intact.