Financier Guy Hands purchased Normanville in Fosse Andre, St Peter Port, for £15.21m. at the end of December.
It is believed to be the most expensive property sale in Guernsey ever. Others have been marketed for more, but have not reached their asking prices.
The open market property covers most of the land between St Jacques, Rozel Road and Fosse Andre.
The property was sold for a nominal £1 in 2009, but had been sold previously for £3.1m. in 1997 and £1.4m. in 1995.
Mr Hands was unavailable to comment on the sale, but the Guernsey Press understands the site has been purchased to allow the property to be renovated.
It would then be used as a very high end rental property for high net worth individuals looking to move to the island or set up businesses here.
Mr Hands founded Terra Firma Capital Partners, which he built into one of the largest private equity investors in Europe.
He moved to Guernsey just over a decade ago and has invested in local businesses, particularly hotels with his wife Julia and their Hand Picked Hotels brand, and property.
Work is well under way on Le Vallon Farm in Ville Amphrey, St Martin’s, with applications from Mr and Mrs Hands over the last seven years to update and expand the site, which was purchased for £7.7m. in 2013.
The latest sales brought to an end a bumper year for property on the open and local market.
Just a few months ago another one of the Bailiwick’s most expensive houses – Maison de la Falaise on Rue du Becquet above Bluebell Wood – sold for just over £13m.