A New York City antiques dealer who admitted he illegally bought rhinoceros horns has been sentenced to six months in prison.

David Hausman also was fined $28,000 in federal court on Thursday for breaking laws intended to protect endangered black rhinos.

The Manhattan resident said in pleading guilty last summer he knew the horns needed to be more than 100 years old to be legal sales. He admitted he double-crossed the U.S. Fish & Wildlife Service by first offering to help fight illegal sales of rhinoceros horns, then buying some himself.

Hausman was arrested in a nationwide crackdown on the black market trade.

Rhino horn carvings are considered good luck charms or health enhancers in some cultures. Authorities say persistent demand for the carvings has devastated the world's rhino population.