Three bears, including a male known as Bernardo, notorious for raiding chicken coops, were found dead of suspected poisoning in the mountains of central Italy. Authorities are hunting now for the killers.
The bears belong to an endangered subspecies, and Italy's forestry service said it had dispatched a team to investigate.
"These criminals must be arrested and sentenced in an exemplary way," Environment Minister Alfonso Pecoraro Scanio said. The local chapter of the World Wildlife Fund offered a EUR10,000 (US$14,000) reward for information on those responsible.
Bernardo was being monitored with a radio collar by researchers, who alerted authorities once they realized he was no longer moving, officials said. His body was found Monday, and subsequently a female bear and a cub also were found dead.
"One death could have been by natural causes, but with three dead bears in the same area at roughly the same time it's clear that there has been foul play," forestry official Luciano Sammarone said.
The animals were among the world's 30-50 surviving Marsican bears - a brown bear subspecies that lives almost exclusively in the mountains of Abruzzo, a region in central Italy.
The death of the young cub and of the female, who could still bear offspring, was a "very serious blow" to the critically endangered animals, Sammarone said.
The bodies were still undergoing autopsies, but officials were convinced the bears had been poisoned. Investigators found several dead goats in the area, and Sammarone said that leaving poisoned carcasses in the forest is a common method used by farmers to target predators that threaten their livestock.
The killing of the endangered bears caused and outcry in Italy and news reports said Bernardo, a symbol of the "Parco Nazionale d'Abruzzo," was specifically targeted by farmers seeking revenge for the food-gathering raids he and his fellow bears often conduct in nearby villages.
Sammarone said the bears generally were tolerated by locals, and that the poison most likely had been intended for more dangerous predators such as wolves. The bodies of two wolves were also found in the area, he said.
In Italy, killing an animal from a protected species can carry a sentence of up three months in jail and a fine in Italy, but politicians and environmentalist were calling for a harsher response.