More than 50 ewes and lambs have been stolen from a field.
The theft happened in a field between the A5 and Litchborough near Towcester, sometime between Wednesday March 30 and 9am on Saturday, April 2, when the theft was discovered.
The entrance to the field is on Northampton Road, just before a sharp bend. Police say they believe a vehicle reversed off the road into the gateway and loaded the sheep.
Witnesses, or anyone with information, are asked to contact Northamptonshire Police on 101.
Alternatively, they can call the independent charity Crimestoppers anonymously on 0800 555 111 or use the anonymous online form at www.crimestoppers-uk.org.