They had purchased in the Mittagong area,  renowned for its picturesque countryside, sprawling properties and grand homes – some commanding prices of up to $6 million.

But between the time they bought the semi-rural property and when they moved in some months later, they discovered something terrible had taken place.

Excavators, bulldozers and trucks had been brought in and the natural ridge line separating their property from three other neighbours had disappeared. So had the old-growth eucalyptus trees on the top of the ridge. They were left with a gaping excavated hole where more than 10,000 cubic metres of earth had once been.

"It was total and utter environmental vandalism", Mr Lorincz said. "Some of the work had even been done on our property without our consent.

"I went immediately to the neighbour and asked him what was going on. He told me everything was approved by council."

But the neighbour, solicitor Paul O'Shanassy had unlawfully removed the hillside and the trees so he could extend his home, capture panoramic views of Sydney's skyline and improve the value of his property – he told people – by $1.5 million, a court has found.

On Friday Mr O'Shanassy was convicted of breaching the Environmental Planning and Assessment Act, fined $93,500 and ordered to pay costs of the Wingecarribee Council of more than $300,000.

Justice Rachel Pepper from the Land and Environment Court found that Mr O'Shanassy had intentionally committed the unlawful earthworks so he could build an "extension to his house in order to take advantage of the view of Sydney".

Justice Pepper found that Mr O'Shanassy knew he was unlikely to get permission from  council  but did it anyway, and his commissioning of contractors to do the work amplified his culpability.

"Mr O'Shanassy's purpose in completing the extension was to increase the value of his property and to improve his amenity by opening up the view. He told people he believed it would 'increase the value of his house by $1.5 million'," she wrote in her judgment. "There can be no doubt that O'Shanassy committed the offence for the purpose of financial gain."

She said he was driven by "mercantile desires" and that part of Mr O'Shanassy's initial account to the court about earlier works was "untruthful".

However Justice Pepper said he had ultimately disclosed the truth. Mr O'Shanassy changed his not guilty plea to guilty after 12 days of evidence in the court.

"I accept this very late change of position by him as sincere. Damascene changes of heart, even if arrived at the gates of the city, can nonetheless be genuine,"  Justice Pepper said.

Mr O'Shanassy declined to comment until he had a chance to review the judgment.

Mr Lorincz said he suffered not only the loss of amenities and substantial damage to his home from flooding he believes was caused by the removal of the natural landscape – but also his faith in the system.

Mr Lorincz  said he had to fight for years to get the council to prosecute Mr O'Shanassy but it wasn't until he threatened to go to the ICAC and the state Ombudsman that action was taken.

"It has been an epic. The greatest impact has been the fact that I completely lost faith in the system, the council, and the law."

Council documents obtained by Fairfax Media show the illegal works had also been carried out on the property of another neighbour – John Uliana​, who is a Wingecarribee councillor.

The council issued Mr Uliana with a notice ordering the earthworks done on his property be reversed and the ridge be returned to its natural state. In July 2012, a motion was passed authorising the prosecution of landowners Mr Uliana and Mr O'Shanassy involved in the unauthorised removal of trees on Lots 11 and 12 Range Road, Mittagong.

Fairfax Media has been told that the work on Mr Uliana's property has not been done. Neither has he been prosecuted. Mr Uliana has previously been reported as saying he knew nothing about the work.

Wingecarribee councillor Gary Turland has put up a motion for the next council meeting urging that the council reinforce its own resolution and prosecute Cr Uliana.

Mr Uliana told Fairfax Media: "It is totally inappropriate for me to comment on a motion that hasn't been presented and could be withdrawn.

"Notwithstanding, I categorically deny any inference of wrongdoing at my former property at Range Road in relation to the subject matter in these proceedings."

He said there was no evidence nor mention of wrongdoing whatsoever in the judgment about Mr O'Shanassy.

The council has refused to comment to Fairfax Media on any aspect of the case.

Mr Lorincz said he still intends to complain to the ICAC.