The dream of every Antiques Roadshow fan is to be that lucky person who dusts off an object from the attic that turns out to be worth hundreds of thousands of pounds – or more.

However, these moments of TV gold are likely to become even rarer, according to one of the show’s veteran experts.

David Battie, a ceramics specialist who appeared on the first episode of the show in 1978, admitted it was getting more difficult to unearth treasures, given how long the show had been running.

“There are definitely fewer really stonkingly good objects on the Roadshow, which is inevitable, given we’ve been going for 40 years, sucking them in like a vacuum cleaner,” he told Radio Times magazine.

Over the years there have been some memorable moments such as the vase a woman bought at a car boot sale for £1 that turned out to be worth £30,000 and a vase used as a goalpost that ended up selling for £668,000.

A forthcoming episode in the new series will feature one of the most significant finds in the show’s history. During filming in June, jewellery expert Geoffrey Munn valued an intricate Fabergé ornament at about £1m.

Despite being on the show since the beginning, it was not until 2010 that Battie made a big discovery when a man brought in a large Chinese bronze vase. He dated it to the Yuan dynasty. At more than 700 years old, it was the oldest bronze to be featured on the Antiques Roadshow.

He said while extremely rare objects such as that were getting more difficult to unearth, they were still out there. “We’re lucky in that in this country that we have more antiques per square foot than anywhere in the world, so I think we have a way to go yet,” he said.

Asked about other memorable moments from his near 40 years on the show, he said a woman once left him a coffee can and saucer from her full service that was dated from about 1800.

“She’d left it to me in her will, saying that because I was so kind and enthusiastic, she’d like me to have a piece when she died. It sits on a shelf in my bedroom and is one of my very favourite things,” Battie said.

In the interview, he also discussed his admiration for the show’s presenter, BBC newsreader Fiona Bruce.

“I think Fiona is wonderful,” Battie said. “Early in her tenure I wrote her a doggerel love poem in the style of the poets I liked, from Edward Lear to Dylan Thomas. She was probably horrified.”

Battie trained as a graphic designer at art school before working for Reader’s Digest magazine for three years. He joined Sotheby’s auction house in 1965 and was later appointed a director of the company.

He retired in 1999 and as well as appearing on the Antiques Roadshow he lectures and writes.