According to locals, developer John Aiken (19) didn't apply for planning permission before ordering his digger drivers to rip out a substantial section of Foughill Mountain, near Jonesborough.
Last month Mr Aiken - who lives in a mansion in nearby Ravensdale - bought a parcel of land overlooking the Irish border between Co Armagh and Co Louth.
But now he's been served with an order by Newry, Mourne and Down Council preventing him with proceeding for 28 days.
He has told people living in the area he wanted to build a new lorry park with warehouses with close proximity to the European Union border.
But when we caught up with him this week, inquiring why he went ahead with the development without planning permission, he told us: "Who owns this land? I do, and I can do what I like."
Local people are up in arms over, what they claim, is Mr Aiken's disregard for planning laws as well as damage to wildlife.
A recent survey of the site - seen by the
Sunday World - reveals it contains several badger runs. And the area - which is just over an acre in size - is also home to roosting bats, red kites and sparrowhawks.
It has never been farmed and in recent years the area has become a favourite with walking groups.
Historian Seamus Murphy - who is originally from nearby Dromitee - joined a small protest at the site on Friday when coincidentally Mr Aiken turned up in his BMW sports car.
He told Mr Aiken that he had done more damage to the hill than the British Army had done when they were stationed there.
"This mountain was here for thousands of years. The people who live around here treat this mountain and surrounding with respect," Mr Murphy said.
"They enjoy it and they have protected it for future generations. The British Army was here for three decades but they didn't do anything like the damage you did, when they left."
Sean Phillips' bungalow home is situated inches from excavated site.
And he is worried in case the work on the site causes his family home to subside. "You can see how close this is to our home. It's literally inches away from this hole in the ground. Anyone can see it is downright dangerous."
Mr Phillips - whose family have been living in the area for six generations - said he had tried on numerous occasions to find out Mr Aiken's plans for the property, but as yet he has been unable to get any definitive answers.
And Margaret Campbell - who helps run the Gap of the North Walkers group - says she was appalled when she saw diggers arrive and start ripping out the side of the mountain.
"This is an area of outstanding natural beauty. People come from all over to see this place now that it is safe to do so.
"As the photographs show, a huge gap has been ripped out of the mountain.
"If this isn't stopped then it will become the norm, not just here, but in other parts of the border region.
"This needs to be stopped and the mountain should be restored to the way it was before these people arrived," she said.
Sunday World has learned that Mr Aiken has been served with a 28-day order preventing him with proceeding with the development.
He told us: "I am only interested in protecting people from getting injured from falling rock.
"Rocks were falling down this mountain onto the road. People could have been injured. By clearing this site we made it safer," he said.
He added: "It's a pity you're doing this story. I have another one for you on the other side of the mountain. And you could have made yourself a few bob."