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The latest thefts of grave plaques have included a bronze plaque honouring the memory of the only New Zealand soldier killed on active service on home soil during World War 2.

Featherston residents are "outraged" over the theft of the plaque commemorating shooting victim Private Walter (Wattie) Pelvin, of Geraldine, the Wairarapa Times Age reported.

Ken Burgiss, of the Featherston Heritage Museum, said the thieves "are just low-life scum".

Pvte Pelvin was shot accidentally by his own comrades when guards at the local prisoner of war camp opened fire on Japanese prisoners on February 25, 1943.

He was killed by a ricochet from a burst of fire which mowed down 109 Japanese, killing 48 of them

His memorial plaque was levered from its concrete foundation at the peace garden and Japanese War Memorial at Tauherenikau - apparently to sell as scrap metal.

The theft is part of a surge of metal thefts including not only brass and bronze plates from memorials but even street signs and posts, sump grates, and farm gates.

In two Auckland cemeteries, metal plaques worth around $100,000 have been stolen recently, including 45 from veterans' graves at the Otahuhu Cemetery last weekend.

Twenty-six plaques were also taken from the Otahuhu Cemetery's public section, and around 30 from Waikaraka Cemetery in Onehunga.

Police and local scrap metal dealers have been advised of the thefts, which follow a rise in scrap metal prices.

Returned Services Association Auckland district president Gary Walker hoped the thefts were not a trend.

"I would hope that any scrap metal merchant that they were taken to wouldn't accept them or would ... contact the police."

Auckland councils have reported a wide range of metal thefts recently, including bronze sculptures and statues, steel rubbish bins, copper flashing and even stormwater grates.

In March last year, 400 bronze plaques were stolen from Purewa Cemetery in the Auckland suburb of Meadowbank - a haul police estimated as likely to cost $300,000 to replace.