A Venezuelan veterinarian wanted by U.S. authorities was arrested by Spanish police. His crime? Smuggling heroin that he implanted in puppies.

Andres Lopez Elorza, 33, was arrested Saturday in the northwestern town of Santa Comba, a Civil Guard spokeswoman said on Tuesday, according to the New York Post. Lopez had been hiding in the small town after the National Court approved his extradition in May.

The spokeswoman, speaking on conditions of anonymity, said that Colombian authorities found 6.6 pounds (3 kilos) of heroin inside of three puppies after a raid on the vet's clinic in Medellin, according to The Guardian. Authorities believe the vet was part of a drug-smuggling ring that used dogs to transport liquid heroin from Colombia to the United States.

Lopez was initially arrested in Spain in 2013, but was let go while the court was deciding whether or not to authorize his extradition. The police spokeswoman said that Lopez had been living in Spain for eight years and was married with two children, according to the Associated Press via Huffington Post. The vet had worked for two different companies and his employers "spoke highly of him." Lopez has no prior record of drug-trafficking in Spain.