A property developer who carried out £1million-worth of work on his Grade II Listed sandstone manor house in Wales without consent has been told to pay £300,000 in fines and costs or go to prison.

Newport Crown Court heard how 60-year-old Kim Gregory Davies ripped out Georgian features of Llanwenarth House and replaced them with 'mock Tudor'. He also installed a mosaic spa bath and used the 100-year-old headstones of children for wall decoration. Cut up gravestones were found in the back garden.

Prosecutor Nicholas Haggan QC told the court that a listed building specialist had described the alterations as being the “worst example” he had seen during his 25-year career. He said the works had affected every part of the exterior and interior of the property.

The seven-bedroom Llanwenarth House is in the picturesque Usk Valley of Monmouthshire. It is where Irish composer Cecil Alexander wrote the lyrics to the hymn 'All Things Bright and Beautiful'. It was one of the earliest properties to be Listed for its important historical character 60 years ago.

Judge Daniel Williams ordered Davies to pay a £60,000 fine by September 15. Davies will also have to pay £240,000 of the prosecution’s £440,000 bill. Those payments will be made in £40,000 installments over a six-month peroid. Davies said he did not have that much money but the Judge said if the fine was not paid in full Davies would get a 20-month prison sentence.

Davies had originally insisted he had done nothing wrong and claimed a since departed planning officer had given him verbal permission to carry out the work. He said he had saved the building from ruin as it was falling down when he bought it in 2007 for £675,000. But he pleaded guilty in court, having faiied in a succession of applications to have the prosecution halted.

After Davies had carried out the work, officials from the Brecon Beacons National Park Authority (BBNPA) received an anonymous tip-off that unlawful renovation work was being carried out. They visited and tried to gain access to the property several times but were refused entry by Davies, who locked the gates to keep them out.

Eventually planning officers discovered that changes had included replacing old doors with modern 'Tudoresque' ones, installing ceiling spotlights and turning a bedroom into a bathroom. A coach house and courtyard had been changed and old cobblestones had been torn up and replaced with flagstone paving.

And the prosecution said Davies had used hard cement for the renovation work instead of lime mortar.

Judge Williams said Davies had turned a precious and beautiful building into a “hidden palace of an iron curtain dictator”.

You can read more about the case and see photographs at Wales Online.