The unnamed owner had believed it was only worth about £300 and had put it out of the way in his loft.
However when the miniature of St Peter went to auction, it went for an incredible £98,000. How incredible is that?!
The price difference is thought to be because it was originally believed to have been painted by a follower of 16th century artist El Greco but the huge price suggests it could be by the man himself.
Richard Bromell, of Charterhouse Auctioneers in Dorset, was quoted in the Daily Mirror, saying: "When I told him how much it fetched he said he needed to sit down."
We bet he did - we're off to search our attics now!
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