Scrap metal recyclers say they should have been told bronze plaques had been stolen from the Wellington Botanic Gardens - so they could help find the culprits.
The plaques, which were taken from from a World War I artefact, a sculpture and several memorial chairs, were stolen from the city's park over the past week.
Botanic Gardens manager David Sole said the scrap metal value was not worth much, but could cost up to $10,000 to replace because of casting costs.
Security was difficult due to the size of the gardens and cameras were not in place, but the police had been notified, he said.
The Scrap Metal Recycling Association said it read about the theft in the media.
Its president, Korina Kirk, said if they had known earlier they could have kept an eye out for the bronze, or bought it and passed the seller's details on to the police.
The association's network could spread the word about stolen metals, she said.