BRITAIN'S biggest lottery winners have put their Scots mansion up for sale for £800,000 after moving to a bigger house.

Euromillions winners Colin and Christine Weir are selling the country pile which was their first big purchase after their huge £161 million win in 2011.

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The couple swapped their modest three bedroom detached home in Largs, Ayrshire, for Knock House, which sits just north of their home town.

They bought the property, which has a spectacular walled garden and breathtaking views over the Firth of Clyde, for £850,000 in August, 2011 - just a month after their win.

They spent the next few years lovingly upgrading the property but have now decided to sell up after buying Frognal House in Troon for more than Pounds 3 million.

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Knock House has five bedrooms, a sun room and a conservatory. There is also a three bedroom gatehouse on the estate for guest accommodation.

It is now being marketed by estate agents Savills for offers over £795,000. No interior photographs of the house are included in the sales brochure.

During their time at the property the Weirs converted old potting sheds in the grounds into a wine cellar and tasting room, a meeting room and an office.

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They also had the walled garden completely relandscaped and commissioned a local artist to create sculptures from fallen trees in the grounds.

The sales brochure for the property reads: "Knock House is a superbly presented country house in a beautiful and private rural setting overlooking the Firth of Clyde and out to the Isle of Bute.

"The small country estate includes the main family house, walled garden, a gate lodge providing excellent guest accommodation and incredibly private garden and paddocks.

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"The whole property has been completely refurbished and embellished using flair and imagination as well as the best materials and tradesmen around. Nothing has been left to chance including electronic entrance gates, back up for power supply and state of the art security systems.

"In the main house the rooms are bright and where possible take full advantage of the great views. It has a beautiful new kitchen, sun room and three new bathrooms."

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The property also has a stable block with two fenced paddocks and a jumping field to the west of the house.

In 2013, the Weirs were sued by a building firm after pulling out of a deal to make lavish improvements to the home.

York-based Oak Leaf Conservatories accused the pair of “unlawfully repudiating contracts” for the design, manufacture and installation of a pool house, a garden house and a conservatory.

However the couple said they had suspended work because they had "lost all confidence" in the builders and a judge at the High Court in London ruled that they could not be pursued through the English courts.

Mr Weir, 69, a retired cameraman for STV and his wife, 60, a former psychiatric nurse, were catapulted into the league of the super-rich after their big win with a Lucky Dip ticket.

They have become known for donating to good causes and set up a charitable foundation shortly after their win.

Last month they donated £500,000 to Partick Thistle's youth academy. Mr Weir is a lifelong fan of the Glasgow club and also ploughed in £750,000 in 2013.

Their new home in Troon, which they bought from restaurant magnate Bill Costley in 2014, sits in 32-acre grounds and features a minstrels’ gallery with a 36,000 piece crystal chandelier.

A spokeswoman for the Weirs declined to comment.

ENDS