A historic courthouse and jail that once held highway robbers and thieves before they were transported to the British penal colonies in the 18th Century has been transformed into a luxury £14.5 million home.

The Court House, on the aptly-named Justice Walk in Chelsea, is one of London's last surviving courthouses and gaols and has been dubbed "Britain's most expensive prison cell" after undergoing a designer restoration and makeover.

Built in the early 18th Century, the majestic house of justice tried hundreds of criminals with highway robbery, drunken behaviour and petty theft - of a kind similar to legendary highwayman Dick Turpin (who was executed in 1739 for horse theft).

The courthouse tried criminals like Dick Turpin (above) and transported them to the penal colonies in Australia as punishment (below)

After being tried in the court rooms, prisoners would be transfered to holding cells in the basement of the building - now a family room and study.

The criminals would then be escorted at nightfall through the dark back lanes of Chelsea to the River Thames, where moored ships would transport them to British penal colonies in Australia as punishment.

Urban legend has it that a secret underground passage connects the courthouse to the docks, as a means of taking the most dangerous prisoners to meet their fate.

Chelsea's courthouse: in the 18th Century and now

Owners Graham and Sylvia Bourne brought the property, which is tucked away in the heart of old Chelsea, for £2.8million in 1998.

Its lavish redesign came about at the hands of Italian artist Mauro Peruchetti, who went to town with a series of intricate interior details such as aromatic Aformosia wood flooring, which changes colour as the sun moves around the house, a Gaggenau kitchen and a state-of-the-art basement gym.

The exterior of the building is steeped in history, with the gated steps that once served the holding cells below the court rooms, now a side access to the lower ground floor.

The main house boasts five bedrooms, each with en-suite bathrooms, as well as luxurious floor to ceiling wardrobes and full height bespoke doors.

The grand master bedroom occupies the entire top floor, serviced by his and hers luxurious en-suite bathrooms, walk-in wardrobes and private studies surmounted by vast skylights and partitioning doors.

There is also a walled terraced garden from the main house and a mews-style guesthouse, providing additional space for guests, staff quarters, or as a potential office space.

What was once the courtroom jail has been transformed into a family room and study (second above). After the courthouse was disabandoned, the property was made into a wine warehouse before being transformed into a series of artists' and architects' studios. This is the first time in its 300-year-old history that it will be an actual home.

Specialist Chelsea estate agents Russell Simpson are selling the property and its founder, Alan Russell said: "The Court House is the jewel in the crown of Old Chelsea, it is a property that truly encapsulates the history of Chelsea.

"From the handsome brick exterior to its monumental double-height sitting room, adorned by marvellous tall original Victorian windows, The Court House has been significantly restored into a diverse property."

Photos: Rex Features