Antiques Roadshow fans will get a peek inside one of England’s oldest and most valuable doll’s houses after the show’s expert, Fergus Gambon, made the discovery of his career.

Fergus, who is the son of Sir Michael Gambon, realised he had found something “of national importance” during the show’s visit to Tewkesbury Abbey in Gloucestershire when he was presented with a box of 300-year-old dolls.

He was even more excited when the owner told him he had the whole doll’s house at home, intact and unchanged for centuries.

Fergus Gambon (BBC)

In a first for the Antiques Roadshow, Fergus jumped in a car with a camera crew and went straight to the owner’s house.

Admitting that the episode was “most unorthodox”, he told the Press Association: “The thing was, as soon as I saw the dolls I recognised the importance of it.

“And it is quite a large object, it’s extraordinarily fragile, it’s not something that you can just shove in the back of the car and bring over. So if we wanted to show the viewers what the house was like, this was really our only chance.”

The family was shocked to hear that their heirloom could be worth more than £150,000.

The valuable doll’s house (BBC)

The doll’s house was built in 1705 on the Isle of Dogs for Miss E Westbrook. It has been in the owner’s family ever since, passing down the female line for generations.

Only a handful of doll’s houses from the period have survived, but this antique – dubbed the Westbrook baby house – is exceptionally well-preserved, with the dolls in their original clothes.

Fergus said it was “one of the most important English baby houses in existence” and it was “quite stunning for it just to turn up like that”.

The antiques expert had seen images of the house in a book from the 1950s, but could only dream of seeing it up close.

The sun is shining, our first visitors have arrived. Join us at Tewkesbury Abbey. #AntiquesRoadshow 2016 has begun!

— Antiques Roadshow (@BBC_ARoadshow) May 12, 2016

“I saw the dolls first and I recognised them immediately from the pictures,” he said.

“The extraordinary thing about the Westbrook is the fact that it’s remained in the family since it was made, and it is essentially a little time capsule.”

He admitted some may be surprised to find a doll’s house could be worth so much money.

“I think that in the world of doll’s houses there is a constant battle in the sense that people can tend to dismiss them, people who are interested in serious works of art and antiques,” he explained.

“Toys have always been regarded as less serious objects because of their nature, and so I think it’s doubly shocking that something that was just made as a child’s toy, as a mere ephemeral object if you like, and here it is and it’s worth all that money.”

The Antiques Roadshow at Tewkesbury Abbey airs on Sunday August 28 at 8pm on BBC One.