Baboons captured after running loose in Sydney's inner west

A male baboon on his way to a vasectomy escaped his transport with his two female companions and ran amok on the Royal Prince Alfred Hospital campus on Tuesday afternoon.

NSW Health Minister Brad Hazzard said the trio were arriving at the facility when a lock on the door of their vehicle failed.

"Last I heard they'd had a good look around the precinct and ended up in the car park where they were behaving far better than what we’d expect of baboons," he said.

"They obviously decided that inspecting the premises was an appropriate way to spend a couple of hours at the hospital."

Video shows several baboons running beside parked cars as people watch in shock on Tuesday afternoon.

Police at Royal Prince Alfred Hospital where three baboons escaped. Credit: James Brickwood

Police went to the car park on Missenden Road and Lucas Street following reports of the escape, and officers from the Inner West Police Area Command Police called in experts from Taronga Zoo to help round up the rogue primates.

"They are currently contained and police are working with experts to safely return them to their facility," a police spokeswoman said.

A spokesman from Sydney Local Health District confirmed three baboons had been found loose on the hospital's campus earlier on Tuesday and there was no threat to the safety of staff, patients or visitors of the hospital.

Mr Hazzard said the baboons were hanging out in a "quiet location" in the car park away from people. The small troupe were recaptured about 7.30pm.

Baboons outside Royal Prince Alfred Hospital in Sydney.Credit: Michael Tran - Twitter

The 15-year-old male baboon and the two younger females were sedated by Taronga Zoo staff and then taken back to the research facility.

A source with direct knowledge of the medical research used by the hospital said the primates were housed in a low-security building but not many people knew they were there.

The baboons are used for studies on subjects including diet, exercise and electric shock.

"When they die, they are used for medical transplants to each other and further experiments," the source said.

Police at Royal Prince Alfred Hospital were able to contain the baboons.Credit: James Brickwood

Mr Hazzard said baboons from the colony bred at a health facility in Wallacia, assisted in a "range of research programs" including for gestational diabetes and kidney disease.

"It’s quite normal and usually at the end of the research as I understand it the baboons go back to their colony," he said.

In 2016, The Sydney Morning Herald revealed several hospitals around Sydney had used baboons from the Wallacia facilities and other primates for medical experiments, including organ transplants from a pig to a baboon.

The three baboons in question were not at the facility for research purposes but were there so the older male could have a vasectomy so he could live "quietly and peacefully" with the rest of the troop in Wallacia.

"They don’t want him to continue breeding with the small troupe he’s in so, in order for him to stay, the decision was taken that he should have a vasectomy," Mr Hazzard said.

A baboon sits and looks out from behind security fencing at the National Health and Medical Research Council facility in Wallacia in Sydney's west in a file picture.Credit: Dallas Kilponen

"The two females were there just to keep him calm."

The Sydney Local Health District spokesman said the male baboon would spend Wednesday resting, and will undergo his procedure on Thursday.

Federal Greens MP and spokeswoman for animal welfare Mehreen Faruqi said she welcomed the animals' bid for freedom.

"I wish them well," she said.

Mr Hazzard said: "I thought I had seen just about everything as Health Minister in NSW, but a baboon threesome enjoying the grounds of Royal Prince Alfred is really surprising."