Russell Crowe's Sweaty Cap Has Now Raised $400k To Help Firies

A sweaty Rabbitohs cap and three billionaires have helped actor Russell Crowe donate $400,000 to NSW firefighters.

Crowe's iconic Bunnies cap was offered up to the highest bidder on his Twitter page for 24 hours, with a promise to donate all the money to firefighters battling more than 150 bushfires burning across the state. 

The Hollywood actor vowed to match the winning number with his own personal donation to fire relief efforts.

As the hours ticked over, the cap was looking to sell for $6,300, until Cannon-Brookes -- cofounder of collaboration software firm Atlassian -- registered his interest.

"Sign it 'Today is the day' and add your name... then find a kid affected by the bushfires and make his day by giving him the hat... then I’ll bid $100K AUD mate," he tweeted on Friday morning, just hours before the auction was to close.

At first, Rusty questioned the legitimacy of the incredibly generous offer.

"Thanks for your bid Mike. I'm a bit wary of taking it seriously," he replied, asking Cannon-Brookes to send him a private message "if you’re genuine".

It turns out Cannon-Brookes was genuine, and the huge bid was accepted. Needless to say, his bid was the eventual winner.

As promised, Crowe doubled the pledge, with a total of $200,000 to be handed out to 20 different NSW Rural Fire Service brigades.

Crowe said $20,000 will go to Nana Glen 1 and Nana Glen 7, the crews that helped save Crowe's home from fierce flames that ripped through his property on the mid-north coast, while a number of other brigades around NSW will receive $10,000 each.

Mike Cannon-Brookes and Scott Farquhar have donated $100,000 each. Image: Supplied

"Russell’s big heart started it," Cannon-Brookes told 10 daily when approached for comment.

"Those [firefighters] are the champions. After weeks of exhaustion, burns, smoke etc defending our bush, our koalas & our houses? Focus on them. Tell their stories."

It only took a matter of hours for more huge donations to roll in.

Cannon-Brookes' Atlassian co-founder Scott Farquhar and his wife Kim vowed to donate $100,000.

"Would love to join the party (unless 3 is a crowd)! The RFS do amazing work. Thank you both for leading the way," Farquhar tweeted.

Ryan Smith, co-founder, and CEO of Qualtrics in the United States then matched the donation.

Smith explained to 10 daily that because Qualtrics has a team in Sydney and Melbourne, he had received a number of internal email communications over the past few weeks "about the smoke, safety and caution".

"We have a lot to be thankful for. We are 'one team' globally and they need our help. Pretty simple," he said.

The NSW Rural Fire Service, seemingly surprised with the donations welcomed the support.

"Wow. Incredible show of support for our amazing volunteers. Thank you," they tweeted.

Thousands of firefighters are battling close to 150 bush and grass fires across the state -- close to half of those are yet to be contained.

There is no reprieve in sight, with hot, dry weather to return this weekend.

While firefighters have saved more than 3,000 homes this fire season, at least 668 others have been destroyed.

A number of homes have also been lost in Queensland as firefighters continue to battle a number of blazes. Those fires have burnt through the equivalent of 235,000 football pitches of bushland.

With summer still to come, these figures are expected to skyrocket.

RFS volunteers and NSW Fire and Rescue officers protect a home on Wheelbarrow Ridge Road near Colo Heights. Image: AAP.

Australians have dug deep, donating millions of dollars to firefighters, victims and animal hospitals.

The largest fundraiser was for bushfire affected koalas. Port Macquarie Koala Hospital started the GoFundMe page after an expected 350 koalas died in the fires.

It's since amassed more than $1 million in donations -- the second-largest campaign in Australia.