By Victoria Gill
Science reporter, BBC News
The judges concluded that the wolf was probably a trained model
The winner of the Wildlife Photographer of the Year award has been disqualified after judges ruled that the featured wolf was probably a "model".
The 2009 winning image, dubbed the storybook wolf, was taken by photographer Jose Luis Rodriguez.
Mr Rodriguez strongly denied that the wolf was a trained animal, according to a statement from the organisers.
His photograph was chosen out of more than 43,000 competition entries in October 2009.
Louise Emerson from the Wildlife Photographer of the Year competition office explained that the judging panel had been "reconvened" and had concluded that it was likely that the wolf featured in the image was an animal model that could be "hired for photographic purposes".
This, she said, was in breach of the competition rules which are made available to all entrants.
"The judging panel looked at a range of evidence and took specialist advice from panel judges who have extensive experience of photographing wildlife including wolves," continued Ms Emerson.
"They also considered the responses to specific questions put to the photographer."
Wildlife photographer Mark Carwardine was one of the competition judges. He told BBC News that this was the first time in its 46 year history that there would not be a winner.
Mr Carwardine explained that he and his fellow judges had gathered evidence and sought the opinions of wolf experts in order to reach their decision.
The experts compared the winning picture to pictures of Ossian, a tame wolf that lives at a zoological park near Madrid called Canada Real.
"You can see several very distinctive markings and the experts all agreed that, yes, it's the same wolf," said Mr Carwardine.
"We disqualified [Mr Rodriguez] and banned him for life from entering the competition again, so I think that sends a strong message."
Mr Carwardine added that Mr Rodruiguez had, throughout the investigation, denied "hiring" Ossian for the photograph. The disqualified photographer maintains that his subject was a wild wolf.
Mr Rodriguez was not immediately available for comment.
"This is very sad and I think it might make us more suspicious of entries that are too good to be true," said Mr Carwardine. But he added that he hoped it would encourage honesty in the competition in the future.
The disqualified photograph will be removed from the Wildlife Photographer of the Year exhibition, which is being held at the Natural History Museum in London. The exhibition tour will also take place without a winning image.
The annual competition is owned by the Natural History Museum and BBC Wildlife Magazine.