Thieves switch police dog for mongrel pup

MEXICO CITY (Reuters) - A top police sniffer dog working for an elite Mexican drug squad was stolen during an airport transfer by thieves who left a mixed-breed puppy in its place, the attorney general's office said.

Rex IV, a highly trained Belgian Malinois sheepdog with a string of drug hauls behind him, was checked on to a flight from Mexico City this week with seven other police dogs bound for an operation in the northern state of Sinaloa.

But when the dogs arrived at Mazatlan airport, Sinaloa, their police handlers discovered a small black mongrel puppy inside Rex IV's cage, with the sniffer dog nowhere to be seen.

"In 17 years I've never seen anything like this. It's rather delicate," a Public Security Ministry spokesman told Reuters on Sunday, adding that the worry was the dog could help smugglers find new ways to conceal drugs.

"It's like kidnapping an intelligence agent," he said.

An airline employee told investigators a man posing as a police officer appeared at the counter and asked to switch the puppy for Rex IV because the Malinois was unwell.

Rex IV is part of an elite Special Canine Unit set up in 2001 as part of Mexico's battle against cartels that smuggle South American cocaine and other drugs to the United States.

President Felipe Calderon launched a new war on drug gangs when he took power in December, sending thousands of police and soldiers to northern and western states where turf wars between rival drug cartels leave dozens dead each week.