The international uproar over an American hunter's killing of a lion named Cecil in Zimbabwe comes amid an intensifying debate over the practice of hunting captive-bred lions in neighboring South Africa.

Ian Michler, maker of a documentary film called "Blood Lions," said Monday that the practice is an "extreme and a brutal form of trophy hunting."

Critics say lions that are bred in captivity are not afraid of people, making them easy targets for shooting in relatively confined areas.

Last month, South Africa's environment minister, Edna Molewa, held a meeting with representatives from the lion breeding and hunting industries to discuss concern about alleged irregularities.

In Zimbabwe, wildlife authorities have said two American hunters were involved in illegal lion killings in separate cases in April and July.