A £14 million project to build a new headquarters for Durham Police has been halted after a rare newt was found close to the construction site.
Taxpayers face a bill of up to £500,000 after the discovery of the great crested newt, which is a protected species in the UK.
Under the Wildlife and Countryside Act 1981, permission for the removal of such newts must be granted by Natural England, the wildlife body that reports to the Department for the Environment, Food and Rural Affairs.
Natural England said it was "working flat out" with Durham Police to resolve the issue.
Planning permission was granted for the new headquarters in June 2012, with completion scheduled for 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."