A vast estate formerly used as a military training area could be given back to its original owners – if only the Ministry of Defence can work out who they are.

Decades ago the British armed forces bought 272 hectares – 2.72 million square metres – of land at Stragglethorpe, near Fulbeck, to be used as an infantry training base.

But after the site closed at the end of March, the government department is now obliged to offer to sell the land, which could be worth around £4m, back to its original owners – or their families - before being able to put it on the open market.

A Defence Estates spokesperson said: "There are relatively few military users of Fulbeck and it is now clear that we can provide the training which our armed forces require at other locations.

"The site, therefore, closed for training on 31 March and we are currently preparing the land for disposal."

But Tony Robinson, vice chairman of Fulbeck parish council said he was unaware of the potential sale.

"You would have thought they would come and speak to the parish council if anything major was happening but we've not heard anything about it," he said.

"We'll just have to wait and see what happens."

The former owners - or their successors - being sought are "John Pratt, Sir Ian Peter Andrew Monro Walker, Sir Edmun Royds and Algernon Henry Mackworth Praed, the Legal Investment and Guarantee Company Limited, William Baines, the Meynell Estates Company, the Right Honourable Rowland Thomas - Earl of Cromer, the Right Honourable Almeric Hugh - Baron Queensborough of Queensborough, and Hugh Mountney Lely.

To stake a claim write to James Ryley, DE Ops North (Disposals), Room F114, Building 351, RAF Brampton, Huntingdon, Cambridgeshire, PE28 2EA before July 17.