A judge has ruled that doctors can take samples of blood from former spy Sergei Skripal and his daughter Yulia in order to be tested by chemical weapons experts.
Both Skripal and his daughter are still unconscious, following a nerve agent attack on March 4, which is why they cannot consent to the tests.
Mr Justice Williams made the decision at the Court of Protection in London, which holds hearing on matters where people do not have the mental capacity to make decisions.
The judge said he had concluded that the sample testing was in the best interests of the Skripals.
The samples will be handed to the Organisation for the Prohibition of Chemical Weapons and the judge said the Salisbury NHS Foundation Trust can also provide the organisation with copies of medical notes.
A private hearing on the matter had been held earlier this week when the judge analysed the situation.
The UK has blamed Russia for the attack on the former double agent, however Russia has denied responsibility.
It has resulted in Theresa May expelling 23 Russian diplomats, but in retaliation Russia has also expelled 23 British diplomats, amongst other sanctions.