An Antiques Roadshow expert mistakenly valued a jug at up to $50,000 (£35,000) - when it was actually a high school student's art project.
Stephen Fletcher was presented with the grotesque face jug - which owner Alvin Barr had found covered in dirt and straw in a barn in Oregon - on an episode of the US version of the programme in January.
He estimated that it was probably made in the late 19th or early 20th century, saying: "It's bizarre and wonderful. You even see a little bit of, like, Pablo Picasso going on here."
The appraiser then amazed Alvin - who had paid just $300 dollars (£205) for the unusual piece - by stating that it was worth between $30,000 and $50,000 (£21,000 to £35,000).
Things took an embarrassing turn when a viewer recognised the piece as something her friend Betsy Soule had made in a ceramics class at Eugene's Churchill High School in 1973 or 1974.
Betsy told the Bend Bulletin paper in the US: "She just called me out of the blue. She said, 'You've got to get on the Internet and look up Antiques Roadshow - that weird pot you made is on there'."
The show's website has since been updated to say that the jug is actually worth between $3,000 and $5,000 (£2,000 to £3,500).
Antiques Roadshow executive producer Marsha Bemko has said that although the experts prepare and discuss items with each other, they do occasionally get it wrong. And she said the jug was particularly hard to appraise.