Scanning a sheep’s eyes produces a unique ‘print’ and means, for the first time, farmers can prove conclusively in court that a particular sheep belongs to them.

The idea came from a police officer in Antrim, Northern Ireland. He noticed that the credit crunch had led to an increase in animal thefts.

One local farmer lost 100 of his top breeding sheep – worth £100 each – in just one night.

Since the programme began 18 months ago, about 3,000 sheep have been scanned across 20 farms.

The process, which costs only £1 a sheep and takes 30 seconds, is done with a £2,500 portable scanner made by Optibrand, a technology company based in Colorado.