An auctioneer was fined £1,000 for trying to sell a chest of drawers containing 100-year-old birds' eggs for £40.
Jim Railton, 57, fell foul of the 1981 Wildlife and Countryside Act by offering the Edwardian cabinet for sale because of what was inside.
He had estimated the auction price to be as little as £40 and even if the cabinet made £100 for his client, he would have pocketed just £15.
Railton, of Chatton, Northumberland, was approached by an NHS executive to sell the cabinet last October through his salesrooms in Alnwick.
The RSPB saw the item – complete with 54 eggs from species including herring gulls and guillemots inside – and informed Northumbria Police. The auctioneer was arrested, questioned and had to give a DNA sample.
James Long, prosecuting, said that, as an experienced auctioneer, Railton should have been aware of the law. Christopher Brown, defending, tried to argue that its was a technical breach of the law and that his client could therefore be given an absolute discharge.
But Alnwick magistrates yesterday fined Railton £1,000 and ordered him to pay £70 costs and a £15 victim's surcharge after he admitted one count of exposing for sale wild birds eggs.
Outside court, the dealer, a former RSPB member and a councillor with no previous convictions, said: "It seems very harsh. I can sell a stuffed golden eagle but if that eagle happens to have an egg in the case with it, it is illegal. What it has cost me in legal fees, fines, time, being arrested, DNA taken, having a criminal record forever – it's way above what I thought."
The eggs will be returned to the cabinet's owner.Reuse content