A wildlife rescue organisation that got $60 million in donations during the bushfire crisis has revealed it was "loath to spend" the massive cash injection.

Key points: WIRES spokesperson John Grant said the charity had not been equipped to deal with the cash influx

WIRES spokesperson John Grant said the charity had not been equipped to deal with the cash influx He said "you're loath to spend it initially because you don't know if it's going to dry up"

He said "you're loath to spend it initially because you don't know if it's going to dry up" The charity's volunteers say more money should have been handed out by now

WIRES, Australia's largest wildlife rescue organisation, has to date distributed only $7 million of the donations it got during the bushfires, which killed over a billion animals.

That's prompted criticism from volunteers, who have raised questions over the way funds are being handed out.

WIRES spokesperson John Grant said criticism of the organisation was "very unfair" and that most injured animals died or were euthanised after being impacted by fires.

"People need to realise those poor koalas captured on camera escaping the fires badly burned wouldn't have survived," he said.

"It broke everyone's heart and prompted donations from all over the world but unless they were lucky enough to have mildly burnt ears and paws, they likely died."

A bushfire-affected kangaroo sanctuary on the NSW Mid South Coast. ( ABC News: Mark Reddie )

WIRES volunteer Mairi MacLeod, from Coutts Crossing in northern NSW, has been a kangaroo carer for 15 years.

She said her branch — Clarence Valley, a region severely impacted in November — has to date received only $10,000.

"They like to keep it in the kitty and I can't comprehend it," she said.

Another volunteer, who spoke to the ABC on condition of anonymity, said she had not received a cent despite caring for half a dozen rescued wombats.

The experienced wombat carer said the charity should have spent more money by now.

"Even $1,000 would have gone a long way to cover fuel — I had to drive from Cobargo to Eden to save wombats," she said.

The carer said she's since learnt she will be reimbursed for petrol and animal food but hasn't found the time to lodge an application.

A platypus rescued by WIRES in the Bega Valley. ( Facebook: WIRES )

'Loath to spend it'

WIRES has said it had provided emergency relief grants to 51 rescue groups across Australia to fund food, water and medical equipment and medications for animals in care and the repair of damaged enclosures of facilities.

Water tanks and equipment have also been funded for volunteers working in search and rescue operations.

Other funding includes the purchase of 26 ICU incubators for care for orphaned animals.

Mr Grant conceded it had not been equipped to deal with the rapid injection of $60 million, but described the criticism as "very unfair".

"We may have been on the backfoot initially but when you're an organisation that has to be accountable for every dollar and rely on public money, you're loath to spend it initially because you don't know if it's going to dry up," he said.

A koala being treated at the Koala Hospital in Port Macquarie. ( ABC News: Kirstie Wellauer )

Mr Grant said WIRES was able to distribute donations to other charities but had to seek approval from NSW Fair Trading to do so, which it was only granted earlier this year.

Mr Grant acknowledged that donors expected money to be spent straight away but said long-term care of injured animals was just as important.

WIRES has earmarked $25 million for ongoing long-term relief and a further $25 million for risk-reduction and a national recovery framework.

"I'm sorry this isn't fast enough for people but this is what happens … there's never been anything on this scale — it's uncharted territory," Mr Grant said.

"One way or another, all of this money will go to the animals."