Whanganui farmers are keeping a close eye on their properties after more than 1400 lambs were stolen from a local farm.
Police said the theft took place in the Fordell area, some time between 27 October and 7 November, and an investigation was underway.
Whanganui Federated Farmers president Harry Matthews said farmers were always on the lookout for strange vehicles or activities on and around their farms.
He said it was hard to have surveillance 24 hours a day, unless cameras were installed, and those could only be located in certain places.
Mr Matthews said flocks in the area could range from 1000 to 15,000 lambs, and the theft could have represented a sizeable chunk of the farmer's herd.
Mr Matthews said it would have taken at least two truck and trailerloads, and about two hours, to transport that many lambs.