Three horses escaped from a Bawsey field after vandals cut the fence.
The animals ended up on the B1145 on Saturday after three strands of fence wire were cut in Chilver House Lane field.
The incident is believed to have happened between 3pm on December 1 and 8pm on Saturday.
All horses were returned unharmed to the field.
Anyone with information should call PC Poppy Thompson at Hunstanton Police Station on 101 or call Crimestoppers on 0800 555 111.