The large eight-year old male, a European brown bear spotted lying on the side of a road by a truck driver, had died a few hours before he was found - almost a year to the day after a brown bear died of poisoning in the same area.
"According to preliminary information, which may be confirmed by other analyses, the death was due to poisoning," the province said in a statement.
There are some 50 European brown bears in Italy, mainly in the mountainous area between Trentino and Veneto, according to authorities, while there are another 50 or so Marsican brown bears - a subspecies - in central Italy.
Reintroduced in parts of western Europe in "rewilding" programmes - in the east they never died out - brown bears have created antagonism among locals in recent years with attacks on livestock.
In 2014, an 18-year old female brown bear with cubs who mauled a man out looking for mushrooms in the north of the country died after being shot with an anaesthetic by officials attempting to capture her.
The bear, Daniza, had been transferred from Slovenia to Trentino as one of 10 brought in to boost the local population in 1999, and her death gave rise to a heated debate in Italy over the European Union-backed project.
Male bears weigh as much as 350 kilos (770 pounds) and females 200 kilos, and they can easily outrun a human. Rearing up, they stand up to seven feet (two metres) tall.
They are omnivores, eating berries and nuts as well as small and large animals - including sheep and calves.
The WWF says the bears play an important role in keeping other animal populations in check and also in "seed dispersal" from their droppings.
Park rangers in Italy say statistically it is more likely that a hiker will fall off a cliff, get hit by a car or attacked by a dog off the leash than be mauled by a bear.