Five graves in the Nowra War Cemetery have been senselessly damaged by vandals.
Five of the 35 marble graves that commemorate World War II Diggers have been pulled from the ground and smashed.
The fragile marble has been in some cases damaged beyond repair.
Well-known local veteran Rick Meehan, who along with his 33-year-old son Luke have maintained the war graves for the Commonwealth War Graves for the past five years, has been left shattered and dumbfounded by the blatant vandalism.
"We cleaned the area last Tuesday," said Mr Meehan who is also chairman of the Keith Payne VC Veterans Benefit Group.
"Everything was fine."
It is understood the vandalism might have happened sometime over the weekend.
"This is just shattering," said Mr Meehan.
I can't understand why someone would want to do this. I'm disgusted, shattered, gutted that this can happen in our society today. I'm just shocked.Shoalhaven veteran Rick Meehan
"Why would anyone want to do this?
"What do they get out of it?"
A visibly upset Mr Meehan said he was left "shaking" when he initially saw the damage.
"I was contacted by War Graves who said there had been a problem at the cemetery," he said.
"When I got up here I couldn't believe it. I can't understand why someone would want to do this.
"I've been looking after this area for about five years, looking after these Diggers who stay here and why someone would want to vandalise it, destroy what they [the veterans] have done for their country is beyond me
"I'm shattered. I can't get over why this has been done."
Mr Meehan said the headstones are invaluable and he questioned where marble to match the other graves could be sourced as a replacement.
"I just can't work out why someone would do this?" he said. "There is no rhyme or reason.
"I'm disgusted, shattered, gutted that this can happen in our society today. I'm just shocked."
Personnel from the Commonwealth War Graves will be in Nowra on Tuesday morning to inspect the damage.
South Coast Police are also investigating the vandalism.
It is the second time in three years the cemetery, which is part of the Nowra General Cemetery, has fallen victim to senseless vandalism.
In August 2016 Swastikas were drawn onto the backs of nine headstones, while more were drawn on a gateway pillar leading into the Naval Cemetery.
All 35 personnel in the Nowra War Cemetery were killed during World War II.
"There are sailors, soldiers and airmen," Mr Meehan said.
"All three services are represented. A number died during training exercises of one sort or another out of Nowra and Albatross."
Their deaths span from 1941 to 1947. They age from 19 through to 35 years of age.
Minister shocked by disgraceful act
Minister for Veterans and Defence Personnel Darren Chester said the desecration of any memorial or gravesite is a disgraceful act.
"But it is particularly disappointing to see the official commemorations for those who have served and died for our nation defaced in this manner," he said.
"The Australian Government, through the Office of Australian War Graves (OAWG), is responsible for the care and maintenance of the official commemorations of over 13,000 Australian servicemen and servicewomen who died during periods of war and over 300,000 official commemorations for those whose post-war deaths were linked to their service.
"The OAWG staff will be working to ensure the vandalised headstones are repaired as a priority.
"There will be no costs to the families of the servicemen affected."
He also encourage anyone with any information to contact police or Crime Stoppers.