Poachers have broken into a French zoo and shot dead a rare white rhinoceros sawing off its horn in what is believed to be the first time in Europe that a rhino in captivity has been attacked and killed.

The four-year-old male white rhino called Vince was found dead in his enclosure by his keeper at the Thoiry zoo and wildlife park about 50 km west of Paris on Tuesday morning after an overnight break-in, the zoo said.

Police, who were investigating the crime, said the rhino had been shot three times in the head and one of its horns had been sawn off, probably with a chainsaw.

Global trade in rhino horn is banned by a UN convention and its sale is illegal in France.