Beagle Watchman retires as NZ's most successful biosecurity dog

New Zealand's longest-serving and most successful biosecurity dog is retiring.

A special ceremony was held on Thursday to commemorate beagle Watchman's nine years of service.

Watchman has kept a tight leash on the nation's borders since 2008, sniffing out thousands of goods that don't pass New Zealand's biosecurity requirements.

He's well known for starring in TV shows Border Security and Dog Squad, with visitors even asking if he's on duty when they land.

"People around the world have seen him doing his job, protecting the country, whether it's at the mail centre, in cruise ship pathways or here at the airport," Brett Hickman of the Ministry of Primary Industries said. "He just does a great job for NZ."

Watchman is the second Ministry of Primary Industries detector beagle to come from English hunting bloodstock.

Good pedigree and his relationship with handler Liz Moore have seen Watchman develop into the country's best sniffer beagle.

"Watchman will be remembered most for his commitment to the job," said Ms Moore, who has been his handler throughout his career.

The ceremony was even more special, as Watchman was joined by his offspring and grandchildren.

Since 1996, MPI has bred 36 litters. Beagle puppies can be adopted by the public for 12 months, until they are ready to be handed back to MPI for training.

Nearly 80 percent of individual puppies have become successful biosecurity detector dogs.

Watchman's legacy will live on, with his offspring training to also become biosecurity dogs.

Moore said Watchman will put up his paws for some well-needed rest and will live with her as a pet. 

"We've been a team for nine years and you know he's my son, really," she says.

Watchman will officially retire on December 31.