The trains are larger than normal models

The haul came from what is thought to be the largest collection of its kind in the United Kingdom.

The models, all hand-made in metal, had been on public display at Keathbank Mill in Blairgowrie.

At the time of the theft, they were stored in boxes. They had been put away at the start of the year, but the crime was not noticed until last week.

Among the haul are 16 green locomotives, 60 green coal wagons, 60 cream and brown coloured goods wagons, 11 Royal Mail carriages and two other sets of 11 carriages.

Either someone has stolen it to order, or they have not realised what they have taken Peter Stewart-Blacker

About 10 of the electric trains, which have great sentimental value, are more than 20ft long.

The building closed as a heritage centre three years ago and is now being turned into flats.

The site on Balmoral Road was a jute mill and has a steam turbine dating from 1862 driven by what is described as the largest water wheel in Scotland.

Owner Peter Stewart-Blacker followed in his father's footsteps as a wood carver, making heraldic coats of arms for organisations such as regiments, embassies and royal warrant holders.

He said: "My father built the collection. It was his last project and it took him 10 years before he died seven years ago.

Collector's item

"This was reputedly the largest O gauge model railway in Britain. I inherited it.

"I can maintain the trains and I have repaired the collection, but my father was the model maker. He was very much a craftsman."

Mr Stewart-Blacker went on: "The whole thing was built to go into the mill. It's painful to have to remove what was left. It's a sorry sight now.

"They are twice the size of normal model trains. To have a sizeable layout would need a very large area. Either someone has stolen it to order, or they have not realised what they have taken."

He continued: "I think it would be worth virtually nothing on the open market. It is a very specialist collection.

"It would need to be sold at a specialist sale. It is very much a collector's item."