Poachers have broken into a French zoo, killing a four-year-old white rhinoceros and sawing off its horn. In the first case of its kind ever in Europe, the rhino named Vince, was found brutally slaughtered in Thoiry, west of the French capital. Horrified keepers discovered the blooded rhino minus its horn when they checked this morning. The raiders had struck overnight. Rhinoceros horns, which are said to be an aphrodisiac, can fetch up to £180,000 on the black market.