Work on a new £14m headquarters for Durham Police has been halted after a protected species of newt was found close to the construction site.
Construction has been unable to take place since a single great crested newt was spotted in October, with delays estimated to have cost about £250,000.
Natural England said it hoped to allow work to continue soon.
Durham Police said it was working with Natural England to resolve the issue "as quickly as possible".
The great crested newt is protected under the Wildlife and Countryside Act 1981 and permission for their removal must be granted by Natural England.
Planning permission was granted for the new headquarters in June and was scheduled to be completed by spring 2014.
A Durham Police spokesman said: "We're trying our best to get this resolved as quickly as possible, but unfortunately we're in the hands of a statutory agency."
A Natural England spokesman said: "We are treating this case as the highest priority.
"We are working flat-out to process the licence application and hope to complete this in the next few days."