In a place where a dementia patient should feel safe, David Nabulsi suffered shocking treatment at the hands of a man paid to care for him.

"It's devastating," Ayda Celine said about watching her father be punched and dragged to the floor of an aged care facility in Sydney.

The confronting footage shows the elderly man being dragged forcefully on a number of occasions and even hit with a shoe twice.

Ayda Celine has spoken about the alleged assault of her father at a nursing home in Sydney's northern beaches. (Supplied)

Ms Celine has hit out at her father's alleged attacker, 35-year-old Prakash Paudyal, who was arrested yesterday and charged with a string of assault offences.

The suspect from Hornsby is accused of entering her father's room in the Bupa aged care facility on Sydney Road, Seaforth, on a number of occasions and assaulting the 82-year-old victim.

The incidents are alleged to have occurred between August 26 and August 29.

Just before 2pm yesterday, Paudyal was arrested at a Wheeler Heights address and taken to Manly Police Station where he was charged with two counts of common assault and use of an offensive weapon with intent to commit an indictable offence.

Ms Celine said her father suffered from dementia and first noticed bruising on his body months ago.

"He was complaining about pain and when I took down his trousers I noticed dark, black bruising that had been there for a while," she said.

"I was advised that he might have fallen, so I let it go".

As the months progressed Ms Celine noticed her father continue to deteriorate.

"He wouldn't let me touch him, and he didn't leave his bedroom or eat."

The incidents are alleged to have occurred between August 26 and August 29. (NSW Police)

Suspecting something more sinister, Ms Celine set up a camera in her father's room which allegedly recorded an attack on her father.

She claims her father suffered shocking mistreatment at the hands of staff at the facility.

"Several times I would call just to speak to someone on the phone to tell them dad wasn't being looked after," Ms Celine said.

A 35-year-old man has been charged over “disgraceful” assaults on an elderly man at an aged care facility on Sydney’s northern beaches. (NSW Police)

"Whether it was bruising or that he was sitting in a wet nappy for hours and in soaked clothes and no one has changed him.

"I installed the cameras because of the bruising and because I didn't trust they were looking after him".

Northern Beaches Police crime manager, Detective Acting Inspector Guy Magee, this afternoon said elder abuse cases went grossly unreported.

"Upwards of 50,000 elderly people have suffered abuse in their lives, with just one in five cases actually reported," he said.

"The bravery of these victims and their families helps bring a resolution to these crimes".

Ms Celine says she feels "like I've failed him" while watching the footage of the assault. (Supplied)

Police allege a male employee at an aged care facility on Sydney Road in Seaforth entered the room of a patient on a number of occasions, allegedly assaulting an 82-year-old man. (NSW Police)

Det Insp Magee said the footage was disturbing.

"I can't imagine what it would be like for the family to watch. It's cowardly, it's disgraceful, and I encourage people to report these crimes to police."

Det Insp Magee said police were fully investigating every complaint made against the accused, "and if there is further evidence (of abuse), he will be prosecuted for that".

Health insurance provider Bupa, which manages the facility, apologised for the assault while Ms Celine criticised the facility's lack of care today.

"Bupa takes the safety and wellbeing of its residents seriously and we are shocked and saddened by what has occured at out Seaforth care home," the group said.