A Labrador named River is patrolling East Anglia's waterways - after being specially trained to sniff out mink which can kill native wildlife.

The 18-month-old retriever has been recruited by the Waterlife Recovery East partnership to protect threatened aquatic creatures from the invasive predator.

River has been trained by owner Stephen Mace to identify the scent of American mink, a non-native species that hunts British species such as water voles, moorhen chicks and kingfishers.

Once she has located them, a floating trap will be put in place and any mink caught will be humanely culled in line with government guidelines.

On her first outing, she located two mink on the banks of the River Wensum at Bintree.

Mr Mace, a project officer for the Norfolk Rivers Trust who lives at St Olaves, between Beccles and Great Yarmouth, said: “River has been trained to locate mink scent since she was just 10 weeks old.

"As a puppy, we practiced only for a few minutes a day, and she would receive a treat reward for successfully sniffing out the mink.

"I’m proud that she has now progressed onto more difficult training, including picking out mink alongside other smells like stoat and squirrel, and receives her favourite ball as a reward."

Mr Mace stressed that River is a "conservation detection dog", not to be confused with hunting hounds.

"She will find the hole where the mink are sleeping and 'mark' it by sitting down, much like a sniffer dog in an airport," he said.

"That tells me there is something there and we can then deploy a floating mink raft with a trap on it."

The American mink was brought to the UK in 1929 to establish fur farms, but escaped into the wild in the 1950s and 1960s.

It is a voracious predator and thought to be one of the main causes of the population collapse of native water voles, which are now under threat of extinction.

Dr Vince Lea, head of wildlife monitoring at the Countryside Restoration Trust, said: “Eradicating American mink from the British countryside is a challenging but important task.

"Mink are a non-native species and excellent hunters, so the increase in populations has caused a serious decline in British river creatures.

"They are also hard to find, so River is a very welcome addition to the team."