It is Scotland’s priciest shooting moor and, its supporters argue, also the classiest.

Millden Estate, after all, was where George VI and his prime minister, Neville Chamberlain, enjoyed some sport just before the onset of the Second World War.

The 20,000-acre estate, one of several landed piles in the Angus Glens, is iconic for supporters of grouse shooting the giant estate. 

Fairly or unfairly, say industry watchers, it has become symbolic for opponents of the industry too.

A decade ago, a tagged golden eagle called Alma was found dead on the estate after being poisoned, leading to a police raid but no arrests or prosecution.  

Eight years ago Millden went on the market for £17.5 million. In the end its owner, London financier Richard Hanson, decided not to sell. But the glossy brochure gave an insight into the scale of the operation.

Agents CKD Galbraith said Millden was “one of the finest sporting estates in Scotland” and “the Holy Grail of shooting”.

At its heart is the 10-bedroom Victorian Millden Lodge and there are two more lodges and multiple other buildings, including three farms and 21 refurbished cottages.

Its grouse moor, in the 2011 ad, was described as “recently rejuvenated”. So much so that its bag is growing: its eight beats have produced an average of 2,352 brace each season over 90 years; in 2010 the figure was 3,033.

The estate also has “established driven low-ground pheasant and partridge shoot” and “eight miles of double-bank fishing on River North Esk with 10 year average of 67 salmon and three sea trout”. 

Mr Hanson, an investment banker, has owned the estate since be bought it from Dame Vivien Duffield in 2004. It is run through a series of companies and a limited liability partnership or LLPs, including one called Millden Sporting LLP, which, as of 2018, reported tangible assets of £17.8m.

The intensively managed grouse estate has been visited by members of the Werritty Review set up by the Scottish Government to look into the future of businesses of its kind. Millden employees have been photographed with Fergus Ewing, the secretary for rural economy.

Insiders say the raid on two of its properties by the Scottish SPCA and Police Scotland has come at a difficult time for the shooting industry, which is eager to distance itself from what it sees as previous bad practices.

The estate itself, it has stressed, is not the focus of  the investigation and it has suspended an employee. 

Dr Ruth Tingay, author of the Raptor Persecution UK blog and a fierce critic of grouse shooting, said: “Millden Estate has been of interest to me since 2009 when a satellite-tagged golden eagle was found poisoned on the grouse moor. 

“This estate is a member of the Angus Glens Moorland Group, feted by senior politicians and held as an apparent exemplar of conservation. I’ll be following this investigation closely”.