Yulia Skripal, one of two Russians poisoned by nerve agent, has been released from the hospital.
BBC News said Tuesday the 33-year-old Skripal had been discharged from hospital and taken to a “secure” location on Monday.
Britain’s Press Association says hospital officials plan to make an official statement shortly.
The British government is likely to keep details about her location secret given the sensitivity of the case.
If she is well enough, she is likely to be extensively questioned by British security officials and police about her recollection of events leading up to her poisoning, which sparked a major confrontation between Britain and Russia that recalls Cold War tensions.
Yulia Skripal was in critical condition after the March 4 nerve agent attack, apparently aimed at her father, former Russian spy Sergei Skripal.
She had arrived on an Easter visit from Moscow the day before the attack.
Her father remains hospitalized but officials say he is improving rapidly.
The 66-year-old Sergei Skripal is a former Russian military intelligence officer who was convicted in Russia of spying for Britain.
He was imprisoned in Russia and eventually settled in England after a “spy swap.”
Britain has accused the Russian government of masterminding the attack on the Skripals, who were found unconscious on a bench in the English city of Salisbury March 4.
British officials say Russia had the means and the motive to attack Sergei Skripal, who was convicted of betraying Russia.
The British government maintains the Skripals were poisoned by a military-grade nerve agent that could only have been made in Russia.
Russia has denied the allegation, but the anger of the incident has led to a mass expulsion of Russian diplomats from countries aligned with Britain. Russia in turn retaliated by expelling diplomats from a number of countries that have sided with Britain.