A 15-year-old male baboon due for a vasectomy and two female companions got loose on Tuesday in a carpark near Royal Prince Alfred Hospital in Sydney's inner west.

Federal Health Minister Greg Hunt said his heart was with the baboons.

"They operated as a modern relationship and I'm fine with that," he told reporters in Canberra.

Greens animal welfare spokeswoman Mehreen Faruqi will on Thursday move a motion in federal parliament noting the primates' "bid for freedom".

Senator Faruqi says the episode highlights the community's concern for animals used in experimentation and research.

She's calling on the government to end the use of animals for research through investing in other methods and technology.

The baboons are involved in research on reproductive issues, kidney disease and gestational diabetes before being returned to their Western Sydney colony.

NSW Health Minister Brad Hazzard said the trio were well and resting.

"Breakfasted on bananas, capsicum, apple & bread after big day out. The tripping trio will rejoin their family (4 other females) post operation tomorrow," he tweeted on Wednesday.

He said the vasectomy had been delayed until Thursday.

Mr Hazzard has rubbished claims from activists the animals were being used for research into human-baboon hybrid organs to address the transplant crisis.

Australian Associated Press