A bird expert has revealed the tactics he used to rescue a curious cockatoo who became stuck inside a shopping centre for weeks and evaded more than 20 attempts at capture.

Mickey the cockatoo became trapped inside Macarthur Square Shopping Centre at Campbelltown in Sydney's south-west last month.

The bird was seen inside and outside the centre's Coles supermarket.

Following multiple failed attempts from residents to catch the cockatoo, wildlife expert Ravi Wasan managed to complete the task on Tuesday morning.

Mr Wasan, who is the director of Feathered Friends Sanctuary in Orchard Hills and from the volunteer-run Sydney Wildlife Rescue, told ABC Radio Sydney he was encouraged to try and coax Mickey out by supporters on social media.

"Everyone was like, 'Surely you can catch this cockatoo',' he said.

He said when he first saw Mickey he appeared "petrified of anyone that looked like they were going to catch him".

"He was spooked by everybody cause everyone tried to capture him with a net or a basket," he told ABC News Breakfast.

"If you had a net or a basket, he was so scared."

To put the cockatoo at ease, Mr Wasan took a female sulphur crested cockatoo named Old Lady Doris from his sanctuary to the shopping centre.

"I brought her in, put her in the shopping centre, and Mickey was so infatuated that there was another cockatoo around," he said.

"She helped me lure him to be honest."

Mr Wasan began giving Doris treats in front of Mickey, which enticed him to approach.

"He watched it and went, 'Alright this guy is not going to grab me'."

"Then I gave Mickey a treat — I tell you what he gave me a good bite at the same time."

While giving Mickey treats, Mr Wasan moved Doris to the other side of a cage he had set up outside the Coles supermarket.

"Mickey followed Doris into the cage and I had this last-minute sprint and shut the door behind him," he said.

Mr Wasan added that Doris "did most of the work" when it came to capturing Mickey.

Environment Minister Penny Sharpe, who referred to Mickey as a "she", said it was a difficult task to capture the cockatoo after the bird "took up residence in Coles".

"People were concerned that people might decide she should be killed rather than captured," she said.

Ms Sharpe said it was "good news" that Mr Wasan managed to capture Mickey.

"She seems to be in very good condition. She has been living off brioche and a range of other snacks at Coles," she said.

Mr Wasan said it took about 20 attempts trying to capture Mickey.

The cockatoo has since been released back into the wild.