Police found the unregistered vehicle parked in a car park near Scratchleys restaurant and Harry's Cafe de Wheels.

Inside the vehicle, with the windows wound up, were 13 cats and seven dogs.

The car smelled like excrement and urine.

A man who owned the car and animals told officials they had been in that state for about three months.

Witnesses had previously reported the vehicle and animals to authorities, but no action was taken.

The situation changed when the vehicle wouldn't start and the man called the NRMA. The police were called last Friday afternoon.

Police asked for council rangers and the RSPCA to deal with the matter. The council said it was an RSPCA responsibility.

The RSPCA did not respond to a request for comment. An RSPCA officer told people involved that action couldn't be taken because the animals had shelter and had been fed.

The RSPCA also told them they would talk to the man about what could be done for the animals. They wouldn't seize them due to questions around whether they had the power to do so.

Dog Rescue Newcastle president Sue Barker said the RSPCA "had grounds and power to seize the animals".

The man was told to take the animals to a shelter, but he was unable to transport them. A social media post called for help and Dog Rescue Newcastle immediately responded.

The rescue group rallied people to help rescue the animals. The man agreed to surrender most of them, but he took two cats to be housed elsewhere. Rescuers took the rest.

One of the dogs, a 14-year-old, was deaf and blind. His teeth were in appalling condition. His mouth was infected. He was "extremely constipated" and his anal glands were impacted.

IN OTHER NEWS:

He had ear mites and his hind legs had old injuries. A vet put him on anti-anxiety medication and antibiotics.

"I rock him to sleep then put him in his crate," his carer said.

Ms Barker said "all the animals are in a very poor state of health".

"It's very disappointing that the RSPCA and Newcastle council both failed to help these poor animals. We spent all Saturday night rescuing them and getting them to carers."

A City of Newcastle spokesperson said "this is a matter for the RSPCA, as it is classed as animal hoarding".

"Any concerns should be directed to the RSPCA for investigation. Information about animal hoarding is available on the RSPCA website."

Ms Barker said "it's animal cruelty and animal hoarding".

She urged the organisations to "work together for a better outcome for the animals".

She said the Prevention of Cruelty to Animals Act should be enforced by the police, not the RSPCA.

She believed many police officers would be willing to "take on the role".