Police and researchers are developing satellite ear-tag technology that could save a lot of time when it comes to tracking down livestock thieves.

Sometimes it can be months before a farmer knows their stock are gone, but the technology can alert the farmer of unusual movements in real time and potentially stop thieves in their tracks.

A world-first trial this week by the University of New England's Centre for Rural Criminology staged a mock theft of 20 sheep to test the capabilities of the tags, which send data from the animal via satellite to a farmer's phone or computer.

Read more at ABC News.