Spanish police have arrested a Venezuelan veterinarian wanted by the US for allegedly trafficking heroin by implanting it in puppies.

Andrés López Elorza, 33, was arrested on Saturday in the north-western town of Santa Comba where he had been hiding after the national court authorised his extradition last month, a civil guard spokeswoman said on Tuesday. The officer spoke on condition of anonymity in keeping with police regulations.

Police said Colombian authorities discovered 3kg (6.6lb) of heroin implanted in three puppies during a 2005 raid on a clinic the vet ran in Medellín. The statement said the vet was a member of a drug-trafficking gang that used dogs to send liquid heroin from Colombia to the United States.

López was arrested in Spain in 2013 but released while his extradition was being considered.

The spokeswoman said López had been living in Spain for eight years and was married with two children. She said he had been working as a vet for two companies, his employers spoke highly of him and he had no record of drug-trafficking in Spain.