Bridges were stolen in Bosnia and Poland in Augus' />

Otago crooks have taken up one of the year's most bizarre international fads -- bridge stealing.

Bridges were stolen in Bosnia and Poland in August this year, apparently by thieves looking to sell scrap metal.

Now Otago conservation officers and police have their own structural dismantling case to crack, and hope someone spots a stack of aluminium panels in the district.

Thieves stole most of the 30m bridge in the coastal Waihola-Waipori wetlands reserve southwest of Dunedin, probably for scrap aluminium, Department of Conservation officer Bill Wheeler said.

The thieves took the aluminium base-plates, side cladding, and one entire section of framework.

Mr Wheeler said DOC could probably claim some insurance, "but I'd much rather have the bridge back".

"If it was left in the corner of a paddock somewhere we'd be happy to go and pick it up," he told National Radio today

Mr Wheeler hopes someone would have seen the theft as he said it would have taken some effort.

"You have to go across the railway line and then through a rather boggy section of wetlands," he said. "It's been quite a manhandling job for somebody.

"Certainly when we put it in we flew it in with a helicopter, so unless somebody had a helicopter up their sleeve to remove it they did a considerable amount of work to take it away."

The bridge was used mainly by hikers, though it was also used for wheelchairs and small vehicles used for wetlands maintenance.

All the aluminium plates, about 1m x 1m, were individually identifiable, he said. Mosgiel Police were investigating.

Seven people were arrested near the Bosnian town of Mostar in late August after locals saw them dismantling a 150-year-old 13m bridge.

Earlier that month a team of thieves took down a 400 tonne steel bridge in the Polish city of Gdansk, making off with an estimated $850,000 in scrap metal.