The painting, signed Turner, depicts the castle overlooking the River Wye, showing the view from downstream of a wooden bridge, complete with a boat in the foreground, alongside a series of cottages.

But after the buyer, who wishes to remain anonymous, discovered a hidden inscription of 'W Turner' on the back of the painting, experts managed to confirm its artistry. It is now expected to sell ...

He painted many river scenes during boat trips along the Thames in his ... Walton Bridges held the auction record for a Turner painting three times in the 19th Century. Its sale for £3.484m ...