Firefighter David Tree and his crew were patrolling land already burnt out by Australia's devastating wildfires looking for flare-ups when he spotted a koala moving gingerly across the blackened landscape.

Local CFA firefighter David Tree shares his water with an injured Australian Koala at Mirboo North after wildfires swept through the region.

"I just pulled the truck over, bailed out and went after him," Tree told The Associated Press on Tuesday. "I love nature, and I've handled koalas before. They're not the friendliest things, but I wanted to help him."

The koala, clearly in pain from scorched paws, stopped when it saw Tree following behind.

"It was amazing, he turned around, sat on his bum and sort of looked at me with (a look) like, put me out of my misery," Tree said. "I yelled out for a bottle of water. I unscrewed the bottle, tipped it up on his lips and he just took it naturally. He kept reaching for the bottle, almost like a baby."

The team called animal welfare officers as it resumed its patrols on Sunday, the day after the firestorms swept southern Victoria state.