Russia implies UK destroyed poisoned spy Sergei Skripal's cat and guinea pigs to 'remove important witnesses'

'Is that what the UK usually does with pets? Is that normal practice?'

Russia is demanding an explanation for the death of Sergei Skripal’s cat and two guinea pigs after they were left in his sealed-off house.

The animals were "important evidence" said Foreign Ministry spokeswoman Maria Zakharova, adding that they had been destroyed by British authorities,

The government confirmed the cat had been found alive but "in a distressed state" at the house in Salisbury.

Found extremely malnourished, officials said the long-haired black Persian was taken to the Porton Down chemical weapons laboratory for testing but that it was in so much pain that a vet decided to put it down.

The guinea pigs reportedly died from dehydration.

Quoting a press report, Ms Zakharova condemned the way the animals had been treated.

“According to the publication, the guinea pigs and the cat were cremated," she said. "In other words destroyed, although the animals could be important evidence in the poisoning case.”

She claimed the BBC had known there were pets in Mr Skripal’s house when it was sealed up but that the information was “hidden”.

“I would like clarification,” she said in a Facebook post, in which she angrily condemned the decision to euthanise the cat.

“It turns out that the Skripals’ pets, in the form of two guinea pigs and the cat, are not alive any more," she wrote. "It's at first glance just an excuse for another joke - 'remove important witnesses'. In fact, they are really 'important witnesses' when it comes to a chemical substance, which, in a number of versions, could have been used in the Skripals’ house.

“According to the British newspaper, the guinea pigs died of dehydration because they weren't taken from the house. What do you mean? Was there a search and no animals? Didn't they notice the pets of the man who was poisoned with nerve gas?!!”

She added: “The cat did it again... Supposedly he (really no one knows what day) was brought to the Porton Down lab and then... drugged. Why drugged? The answer is because the cat was ‘stressed’, since he was ‘not noticed’ in the search. Is that what the UK usually does with pets? Is that normal practice?”

Moscow raised concerns earlier this week over the animals' welfare.

A UK government spokesman said: “When a vet was able to access the property, two guinea pigs had sadly died. A cat was also found in a distressed state and a decision was taken by a veterinary surgeon to euthanise the animal to alleviate its suffering. This decision was taken in the best interests of the animal and its welfare.”

News of the creatures deaths comes, as it has emerged that Yulia Skripal's condition is improving after both she and her father were infected with the Novichok nerve agent last month.

She said she was “getting better” in a phone recording played by Russian state television.

The highest concentration of the nerve agent was later found on the front door of Mr Skripal's home. His condition remains critical but stable, according to NHS England.