The programme, screened on Remembrance Sunday, told the story of a company of soldiers drawn from workers on the Royal estate at Sandringham, Norfolk.

All the soldiers disappeared during fighting at Gallipoli

The company vanished during heavy fighting at Gallipoli in 1915 and exactly what happened to them is still a mystery.

But the BBC drama showed many of them, including the captain Frank Beck, being executed by the Turks.

Earlier in the week, the Turkish Ambassador Ozdem Sanberk, expressed his disappointment at the conclusion to All The King's Men. Mr Sanberk called the drama "very upsetting to the Turkish people" and "certain to reopen old wounds".

Frank Beck's grandson, 71-year-old Edward Hunter, from Berwick in Northumberland, has added his own criticisms, saying the ending was not based on any evidence or fact.

He said: "That I think is distasteful and I don't think there is any evidence to say that is what happened.

"It would have been better and probably more truthful if they had just disappeared into the mist."

He added: "It's quite likely that many of them were simply killed during the assault. The Turks were defending their homeland and the fighting was heavy.

Frank Beck's grandson says Jason's acting was "excellent"

"And it's known that the Sandringham company did get ahead of the line. I think the ending has upset quite a few people."

Nevertheless, Mr Hunter was impressed with the way Jason portrayed his grandfather.

"I thought he was excellent," said Mr Hunter. "I didn't realise how good he was. I was very impressed by him.

"He came to have lunch with me to talk about the project and I liked him enormously".

Mr Hunter said David Jason had advised many of the young actors to visit memorials to men killed during the First World War so they would begin to understand some of the sacrifices made.

At Easter an exhibiton will open on the Sandringham Estate in memory of the men who died at Gallipoli.

Among the exhibits will be a replica pocket-watch specially made by the BBC for All The King's Men.

BBC props will be in Sandringham exhibition

The orginal watch belonged to Frank Beck and was presented to him before the company's departure in 1915 by Sir Dighton Probyn, household comptroller to Queen Alexandra, George V's mother.

After the war, a Turkish general sold the watch to British officials for £10 claiming that it had been found near where Mr Beck fell.

It was presented to Mr Beck's daughter, Alexandra, in 1922 and remains in the family's possession.