New Zealand must have been hoping that the recent sentencing of the man who stole several Victoria Crosses would be the last it heard of medal theft for some time.

However, a Kiwi museum has discovered an old theft of 30 medals in the course of an audit.

The theft is thought to predate the notorious 2007 one. It was only discovered at all when one of the medals was spotted on eBay.

The Te Awamutu museum in Waipa responded with a thorough audit of its inventory including 175 medals and concluded that 30 medals were missing. Checking all its items will take much longer however.

It has been claimed by some - including Jan White of Waipa District Council - that the museum trust was run by volunteers until 2005, though the museum's trust denies this.

At present, the museum has not released details of which medals have been taken, so as not to pre-empt the police investigation.

The medals lost have apparently never been displayed. Unlike the 2007, theft it is unlikely they include any Victoria Crosses, nevermind the Victoria Cross and Bar (double VC equivalent) belonging to Charles Upham.

Nevertheless, they are likely to include some significant valour medals.

Collector and researcher Phil Beattie - who played a crucial role in returning the eBay medal - estimates they may be worth anything up to NZ$50,000 (about US$36,500). 

He fears they are lost, as they could have passed through many hands by now and will not likely appear on the open market any time soon.

The decoration found on eBay, a South African war medal, was won during the Boer War by soldier George Osborne.