The deflated duck, used by the company for promotional work, was found in the harbourside industrial area on Monday.
Mr Sherson said the 3m-high duck was moored behind locked gates, but it appeared someone swam out in the Steamer Basin on Saturday night to get to it.
Once removed from the harbour, the duck appeared to have been dragged behind a vehicle, leaving it riddled with holes and covered with black marks.
The company had the duck made to order about three months ago and he doubted it was salvageable.
Ray White Dunedin director Peter McCrea, speaking from Christchurch yesterday, said the duck was worth about $2000.
''I'm not that happy about it [the theft].''
The duck floating in the basin the past month had brought joy to many people, he said.
