An activist said Saturday that orangutans in many of Indonesia's zoos were allowed to smoke as visitors could freely toss cigarettes to them without proper monitoring.

"Cigarettes are bad for orangutans' health. We demand the zoos closely monitor the orangutans," Centre for Orangutan Protection campaigner Hardi Baktiantoro told AFP.

"Orangutans can also smoke cigarettes because they tend to imitate human behaviour," he said.

Baktiantoro said the apes were able to receive any food or cigarettes thrown to them as there were no barriers between them and zoo visitors.

In Malaysia, an orangutan named Shirley that amused visitors by smoking cigarette butts thrown into her cage was being forced to go cold turkey after authorities seized the great ape from a state-run zoo last week.