Five-bed beachfront mansion with its own infinity swimming pool, cinema room and wine cellar to become the most expensive property ever sold on the exclusive Sandbanks peninsula after £15m deal struck

A luxury house is set to become the most expensive property ever sold on Sandbanks after a £15m deal was struck to buy it.

The five-bedroom beachfront mansion, which has an outdoor infinity swimming pool, belongs to an entrepreneur who grew up in a council house.

Robert Kay bought the property on the exclusive peninsula in Poole, Dorset, for £4m back in 2013.

He spent a small fortune renovating the large detached house before putting it up for sale for £15m.

It is now under offer and will beat the record property price for Sandbanks that currently stands at £13.5m - paid for a bungalow on the largest plot on the peninsula last year.

When the sale is rubber-stamped it will not only be a record for Sandbanks but will also be Britain's most expensive beachfront home.

Mr Kay, a self-made businessman, left school at 14 with no qualifications. He started a video rental business in the 1980s and made enough money to invest in the property market.

The modern mansion, called Flag House, backs directly onto Sandbanks beach and has stunning views over Poole Bay.

Estate agents Tailor Made describe it as the ultimate Sandbanks 'superhome'.

It has almost 8,000sq ft of living space with a huge entrance hall, kitchen, dining room and lounge that all have sea views.

There is a gymnasium, state-of-the-art cinema room, office, wine cellar and boot room on the ground floor.

Upstairs there is a massive master bedroom suite that also has stunning sea views, en suite bathroom and dressing room along with four more bedrooms, three of which are en suite.

One bedroom has privacy glass, which changes from clear to opaque at the touch of a button and there is air conditioning and an integral Sonos sound system throughout the house.

Outside there is a large sun terrace, a swimming pool, hot tub and landscaped gardens with a gate that leads directly onto the beach.

Robert Dunford, from the estate agents Tailor Made, said when the house went on the market: 'We believe this property is Britain's most expensive beachfront property.

'There are luxurious homes in coastal hotspots like Cornwall, Jersey and Guernsey that are on for more but they are all inland.

'This house has direct beach access, there is no road or path or clifftop in the way.

'The property was very tired looking when our client went in there.

'Externally, it is slightly understated in appearance. It is not a modern contemporary home with straight lines and right angles. It has been sympathetically refurbished.

'Inside, no expense has been spared. The owner stripped it right back and redesigned it all.

'The table in the dining room was designed and made by the same people that make Sunseeker yachts.

'The grounds of the property are stunning and could easily be mistaken for a scene in Miami or LA.

'The upper garden is elevated, giving privacy and maximising views and the lower garden offers direct access onto the award-winning Blue Flag sandy beach.

'The location brings with it the lifestyle. You have Poole Harbour, award winning sandy beaches and the Jurassic Isle Of Purbeck as your playground.

'That interest is driving up demand for beachfront and waterfront homes of which there is a finite number on the Sandbanks peninsula.'