Cyanide vials inside an ammunition box have been discovered on a residential property in the Waikato after a dog dug it up.

The box was found yesterday at a property on Maungakawa Rd, which is between Cambridge and Matamata, and police were notified today they said.

"The person was alerted because their dog dug it up," said a police spokesperson.

Police, Fire and Emergency and WorkSafe are now discussing how to best proceed.

A police spokesperson said that as far as they can tell, the box remains in the spot where it was dug up from.