An Antiques Roadshow presenter drank 150-year-old urine thinking it was port.

Glass specialist Andy McConnell inspected a sealed bottle from the 19th century on the BBC show, and decided to sample its mystery contents in front of an expectant audience.

Presenter Fiona Bruce had unfortunate news for Mr McConnell, telling him that expert analysis of the antique bottle’s “very brown” liquid revealed it to be an unwanted vintage.

The glassware antiquarian sipped the well-aged urine when valuing a bottle in Trelissick, Cornwall, for a 2016 programme, after the item was found buried under the threshold of a local man’s house.

Mr McConnell used a syringe to transfer a sample from the bottle to a tumbler, and sipped at the mystery beverage.

“It’s very brown,” he told the audience at the time. “I think it’s port. It’s port or red wine, or it’s full of rusty old nails and that’s rust.”

In a programme broadcast on Sunday, Fiona Bruce delivered bad news to the specialist, after experts at Loughborough University had analysed the contents of the bottle.