A national park authority will be seeking costs against a radio company after it threw a planning appeal into disarray by submitting a stack of new evidence just days before the hearing was due to take place.

Airwave O2, which runs the emergency Tetra radio system used by the police, sought permission for a 10m (33ft) radio mast in the Dartmoor national park. The application was turned down by the Dartmoor National Park Authority’s development control committee last year, leading to a public inquiry.

The company wants to put up the structure at Glebe Farm, Widecombe-in-the-Moor.

Last Friday, Airwave O2 submitted an extra 135 pages of material. The park authority says rules governing such hearings dictate evidence be exchanged four weeks before the start of proceedings. The inquiry is due to begin tomorrow, 22 October.

In the light of the new evidence, the national park authority said it will now withdraw from the appeal. This evidence includes the fact that masts elsewhere in the park would have to be nearly doubled in size if the Glebe Farm aerial is not erected.

Nigel Hoskin, chairman of the Dartmoor National Park Authority, said: “If this information had been presented to members when they were considering the planning application at committee, it would have addressed many of their concerns and I have no doubt that it would have made a fundamental difference to the debate.”

The authority said it will press for costs against the company on the basis of Airwave’s unreasonable behaviour in the appeal. It will also seek rigorous conditions to ensure that the visual impact of the mast is minimised and the background tree cover at the site retained.

No-one from Airwave O2 responded to grough’s requests for a comment.