Video report by ITV News Meridian's John Ryall
The illegal smuggling of high-value puppies from eastern Europe into Kent and Sussex has soared as criminals exploit unprecedented demand for pets during lockdown.
Animal welfare campaigners from the Dogs Trust have secretly filmed at puppy farms, in Poland and Romania, where smugglers pay around £100 for puppies that sell for thousands in the UK.
It means riches for the smugglers but misery and death for many of the animals.
There are so many concerns with this trade, it's the conditions that these pups are being bred in, it's the abuse of animal welfare in how they're being transported across to the UK, it's the behavioural and medical issues that they're coming across with. We're seeing higher mortality rates as the condition of the pups is getting worse and worse.
Many smugglers have been caught coming through Dover, with puppies as young as five weeks old.
Smuggling expert, Adam Levy said: "They're being brought in illegally. They should be 15 weeks old to be legal and that's just not the case with many of them.
"The average age we're seeing is about 8 weeks of age, with the worst cases being about 4-5 weeks when they should be with their mums still."
The Dogs Trust has now rescued 1,500 puppies from smugglers.
The animal welfare charity estimates that the trade soared by more than 60% in 2020.
This Spaniel puppy was one of five found hidden in a small cat carrier at the Port of Dover.
Four were found to have the deadly dog disease parvovirus.
The resale value of puppies, intercepted by The Dogs Trust since 2015, is more than £3 million. But the charity says that figure is a fraction of the total trade.
The trade can be as lucrative as drugs or people smuggling but it rarely results in a prison sentence.
The Dogs Trust is calling for urgent Government action.
Hannah Evans, from The Dogs Trust said: "For us there's two key things that the Government can do right now that would help end this trade, which is increase the age at which puppies are allowed to be brought into the country, to six months which would reduce the market here in the UK.
"But also they need to increase the penalties for those caught illegally importing puppies.
"At the moment, there's very few people who have been prosecuted and those that have, have got such paltry sentences that it's no deterrent whatsoever."