Eight lions from a pride that featured in the BBC TV series Big Cat Diary have been poisoned in the Maasai Mara in Kenya.
The lions from the Marsh Pride appear to have eaten the carcass of a cow laced with poison on Sunday. A lioness known as Bibi - a favourite among viewers of Big Cat Diary - is reported to have died after being discovered foaming at the mouth and panting frantically.
Kenyan authorities have arrested three Maasai herdsmen after the lions killed two of their cows. A fourth suspect is still at large, said Moses Kuyioni, the reserve's chief warden. If convicted, they face a maximum fine of 20 million Kenyan shillings ($295,700) or life imprisonment.
The Maasai Mara National Reserve is surrounded on three sides by an increasing population of herders and villagers who are desperate for land. Every night, thousands of cattle are driven into the reserve for grazing. Lions often hunt these animals - and Maasai herders retaliate by poisoning the predators.
Brian Jackman, a safari expert with Telegraph Travel, named the stricken pride when he co-wrote the book The Marsh Lions, which inspired the BBC series.
Having watched the pride since 1982, Jackman described the poisonings as a bereavement. "I'm absolutely heartbroken," he said.
"They were beautiful, mature adult lionesses. Bibi was one of the great Marsh matriarchs. They were so well known that you would recognise them as you would your own cat or dog or member of your own family. You get to know their whole life."
Jackman added: "This is not just about the wider tragedy of these deaths adding to those of lions all over Africa, but a real bereavement."
Fewer than 2000 lions are left in Kenya " and they are being killed at a rate of 100 every year.
There was confusion about the fate of the lions. AP reported that two had died and the BBC said that two lions were killed, one is missing and eight are being treated.
However, the Kenya Wildlife Service said that all eight lions belonging to the Marsh pride had recovered and were no longer showing "visible signs of poisoning".
A statement from the Wildlife Service appeared to suggest that Bibi was alive and another dead lioness had been mistaken for her.
The constant overgrazing of the Maasai Mara Reserve is having severe consequences.
"The illegal nightly invasions of livestock have reduced much of the grasslands to a virtual desert, so devoid of life that there were not even enough food for once common bird species such as kori bustards and black-shouldered kites," said Jackman.
The poisoning comes five months after Cecil the lion, fitted with a tracking device as part of study by Oxford University's Wildlife Conservation Research Unit, was killed by an American hunter, Walter Palmer.