Northern Ireland is a backdoor for a multi-million pound illegal trade in puppies from the Republic of Ireland into Britain, a BBC investigation has found.

Some of the animals are changing hands for large sums as demand for dogs during the Covid pandemic rocketed.

The BBC NI investigation showed that hundreds of pups, bred in the Republic of Ireland, were being illegally moved to Britain through ports in Northern Ireland.

The Spotlight programme followed dealers who exchanged dogs in service station carparks and laybys for onward transport to Scotland by ferry.

It reported that many of the pups originated in the Republic and were chipped when they crossed the border, allowing them to be sold at a much younger age than under Irish law.

It was claimed the chips used were often unregistered, making the animals impossible to trace.

Many of the pups were malnourished and diseased; a number of them died in transport or shortly after being sold to unsuspecting buyers.

The USPCA has published a report on the puppy trade in NI.

Chief Executive Brendan Mullan said its "shocking scale and ruthless nature".

He said up to two thirds of the dogs shipped to Britain came illegally from the Republic of Ireland.

"We have a very grave issue at hand which is causing unthinkable suffering to the thousands of dogs who are only seen as commodities by those engaged in this cruel trade".

He said regulation inspection and enforcement needed to be much more robust.

Northern Ireland's Department of Agriculture and Environment said it was aware of what was going on and had been trying to stop it.

Minister Edwin Poots said it was an "abhorrent trade" and the information in the Spotlight programme had been passed to officials who had begun an investigation.

He said pups had been intercepted at the ports including ten Springer Spaniels found earlier this month.

"While my officials take all the steps they can, in conjunction with other agencies, to verify details of all notified pup movements, it is not possible nor practical to stop every vehicle moving through Northern Ireland's ports," he said.

Mr Poots said any prospective dog owner should either adopt, or buy only from legitimate licensed breeders.