THE son of one of Britain's richest men has a criminal conviction and was fined £40,000 after stripping a listed country mansion of its historic assets - without permission - so his mother could move in sooner.

Richard Sykes carried out extensive works to a Regency property in Copt Hewick, near Ripon, magistrates in Harrogate were told.

He bought the property, which boasts eight double bedrooms and is valued at £4.5m, for his mother, Valeria in December 2011.

Mrs Sykes' 44-year marriage to UKIP'S principal European elections donor, property tycoon and Sheffield Meadowhall creator Paul Sykes - whose fortune was once estimated to be £650m - had broken down months earlier.

Weeks after he bought the property his father was quoted as saying: "‘I would sooner have stayed a tyre-fitter, where I started. Money just brings a load of lumber."

John Hunter, prosecuting, said Richard Sykes, 49, launched into a wide-ranging overhaul of the historically important property - which was built in 1775 and features an tree-lined drive, orangery, children's sitting room, coach house, swimming pool, gymnasium and Mediterranean entertaining courtyard.

Before the sale, estate agents Blenkin and Co described its period features as having been  "painstakingly preserved", adding: "No detail has escaped the current owners’ meticulous programme of works."

When a Harroagte Borough Council officer visited two weeks after the sale, he was stunned to find substantial changes - including the removal of decorative mouldings, doors, window shutters, floors and ceilings.

Mr Hunter said the works resulted in a substantial change in the building's historic significance.

He added that, despite repeated warnings to stop the alterations, Richard Sykes continued his programme of works for 18 months.

Chartered surveyor Sykes, his Thirsk-based firm West Park Services, and builder Nicholas Hull, 48, of Harrogate, and his firm Thermotech, all admitted breaching the Listed Buildings and Conservation Act.

Paul Greaney QC, mitigating, said the house had not been perfectly preserved and Mrs Sykes had even found some MDF doors after moving in.

He said Richard Sykes had not been "cocking a snook" at the council, and despite period features such as the floating bubble glass windows being lost forever after they were replaced with modern flat glass for clearer views, the property had been improved.

"It is not a building of the highest significance like Castle Howard," he added.

"The drive of the defendant was to return the hall to its former glory, certainly not to turn it into some sort of Premiership footballer's pad.

"No expense has been spared to bring that dream into reality."

Magistrate Alison Stockdale said Richard Sykes, of Asenby, near Thirsk, had shown an increasingly flagrant disregard for the law and fined him £26,010, his firm £14,010, and order him and his firm to pay £26,000 costs.

Hull and his firm were fined £8,660 and ordered to pay £10,000 costs.