RUSSIAN scientists tortured and killed ­thousands of dogs in horrific experiments while honing the nerve toxin which poisoned Sergei Skripal and his daughter Yulia.

Terrified animals were forced to wear gas masks and walk on treadmills until they died from exposure to Novichok.

4 Terrified animals were forced to wear gas masks and walk on treadmills until they died from exposure to Novichok

4 Scientists were honing the nerve toxin which poisoned ex-spy Sergei Skripal and his daughter Yulia

Judith Miller, a US expert, told of her horror at seeing the torture chamber at the Chemical Research Institute abandoned by the Red Army in 1992.

The compound near Nukus, Uzbekistan, was built by the Soviets to manufacture Novichok.

The first batches were shipped to Moscow’s Institute of Organic Chemistry and Technology.

A more potent version was then perfected and sent back to Nukus for the animal experiments.

4 Ms Miller said the dogs were strapped to treadmills and crammed into gas masks Credit: Andy Weber

4 Chemical Research Institute in Shikhany Credit: East2west News

Ms Miller said: “I saw hundreds of small cages where the dogs were held and 25 miniature treadmills.

"The dogs were strapped to them and crammed into gas masks.

MOST READ IN POLITICS BAD NEWS AT TEN Boris to slap 10pm curfew on pubs from Thursday to avoid second lockdown RAPE HELL Schoolgirl, 16, ‘gang-raped, killed and dumped to slowly die on building site’ GRINCHES Mum reveals HUGE Xmas gift haul for daughter - but some parents brand kid 'spoilt' BAG FOR STRIFE Council sparks panic with call to prepare bag to 'flee home immediately' CORONA CRACKDOWN Sadiq Khan calls for masks to be worn in pubs & restaurants across London 'TOUGH S**T' Lawyer refuses to scrap 'offensive' LGOPNR number plate.. can you work it out?

"Thousands died from exposure to the agent.”

Uzbek officials arranged Ms Miller’s visit after the Soviet Union collapsed.

The Shikhany Institute in south eastern Russia also tested chemical and biological weapons including Novichok on dogs.

GOT a story? RING The Sun on 0207 782 4104 or WHATSAPP on 07423720250 or EMAIL exclusive@the-sun.co.uk