IT must have been a dead easy kill. Two former Colombian circus lions — one with brain damage — which, even if they were abused by humans, were also used to them, butchered in the sanctuary where they were supposed to live out their days in peace.

Their heads, paws and tails were cut off and their carcasses left behind, suggesting that the kill was the work of local muti hunters rather than poachers hoping to sell the bones to the lucrative Asian medicinal market for use as a substitute in tiger-bone wine.

The recent killings have up stirred up the bitter controversy over the breeding and hunting of captive lions.

There is a scene in Blood Lions, Ian Michler’s shocking documentary about canned hunting and lion-breeding farms, in which cameraman Nick Chevallier is threatened by a lion farmer.

“I’ll kill you. Don’t take a photo of me. I’ll fucking kill you … Shut your fucking mouth … Nothing’s happened, it’s what will happen.”

It is an ugly moment that does South Africa’s private lion farmers no favours. And watching Blood Lions, it is difficult to feel sympathy for the 200 or so farmers who between them own an estimated 8 000 lions, and whose businesses are now threatened by a US import ban on lion trophies.

The film and the illegal killing in 2015 of Cecil the lion at the edge of Hwange National Park in Zimbabwe fuelled lasting public outrage. In March 2015, Australia banned all imports of lion trophies in a stated attempt to crack down on canned lion hunting. In October last year, the US Fish and Wildlife Service followed suit with a ban on imports of trophies taken from captive-bred lions.

Since South Africa is the only country in the world where lions are farmed for hunting, the US ban will hit the industry — driven mostly by US hunters to the tune of about R100 million a year — hard.

There are, of course, complications. Because the US ban covers only captive-bred lions, anecdotal evidence suggests that some farmers may be looking for ways to present their lions to would-be hunters as wild.

There is another issue. The trade in lion bones — used to make a medicinal “tiger-bone wine” — is legal and demand has soared since China banned the use of actual tiger bones in 1993.

It is very likely, say some conservationists, that South Africa’s captive lions might in fact be a buffer against poaching.

“South Africa is the only country that has lion farming but it is also the only country where all wild lion populations are increasing,” said independent environmental economist Michael ‘t SasRolfes. “We need to understand why this is happening.”

The knife-edge on which activists and conservationists are walking is what a blanket ban on the trade in lion parts would do to wild lion populations.

“If the supply is suddenly cut off, it might well precipitate a lionpoaching crisis,” said ‘t SasRolfes. And the biggest likely loser would be the wild lion.

Africa has lost 43% of its wild lions in the past 20 years, according to a survey led by big-cat research organisation Panthera. The population is estimated at 20 000 throughout Africa, with just six countries harbouring more than 1 000 individuals each.

The decline — from more than 800 000 a century ago — has been driven by habitat loss and human conflict, specifically with cattle herders and ranchers.

“Contrary to popular belief, trophy hunting is a small factor in the fate of the African lion,” says the report.

But African herders killing lions in revenge for losing cattle do not make headlines; a rich American dentist shooting a big black-maned male lured from a national park does.

That rich hunters from the West are willing to pay eyewatering fees to shoot lions is not in doubt. Prices for a male lion range from around $16 000 R205 000 to $32 000.

While breeding lions just to shoot them is highly questionable on moral grounds, there is a case to be made for ethical hunting.

“I approve 100% of hunting,” said conservationist and former park warden Paul Dutton. “Every single protected area in South Africa was created by a hunter.”

Ethical hunters follow the principles of “fair chase” — the pursuit of a free-ranging animal living in a wild, sustainable population and which has the instincts and ability to escape from the hunter.

“I would prefer,” said Dutton of those pressed-for-time foreign hunters who want to bag their lions in a matter of days, “that these big, fat arses go and hunt [the lions] on foot in the bush. Then we’ll see who wins.”

South Africa’s lion farmers are confronting a crisis. Part of it is self-inflicted, with some rogue farmers and unethical breeders tarnishing the industry.

“Of course there are atrocities and these need to be stopped,” said ‘t SasRolfes.

For the others, what happens is largely out of their hands. Trade policy and decisions will be made in faraway corridors of power by people who may have little grasp of the realities on the ground. More transparency and some serious self-regulation could help swing public opinion in their favour.

And the wild lion might see out this century.