More than 300 rounds of police ammunition has gone missing while in transit between Auckland and Wellington.

A police spokesperson confirmed to the Herald that a freight company reported the loss of ammunition on Thursday.

“The amount of ammunition missing is believed to be 10 packets containing a total of 320 rounds from a larger consignment of ammunition,” the spokesperson said.

The missing ammunition was destined for police. It left Auckland on September 28, and upon arrival the following day it was noticed that a carton containing the ammunition was open.

“Police are in the early stages of investigating this incident and are treating it extremely seriously.

“Due to the ongoing investigation police are not able to comment further at this time.”