LONDON — Yulia Skripal, who was poisoned in a nerve agent attack alongside her father, a former Russian double agent, was discharged late Monday from a hospital and taken to a secure location, her doctors said Tuesday.

Skripal, 33, recovered more quickly than did her father, Sergei Skripal, 66, who is awake and responding well, said Christine Blanshard, medical director of the district hospital in Salisbury, in southwest England, where the March 4 attack took place.

A Salisbury police officer who was a first responder at the park bench where the two Skripals were found was also treated at a hospital and released last month.

“All three had been exposed to a nerve agent. In the past weeks, both Sergei and Yulia have received round-the-clock care,” Blanshard said. “I won’t go into great detail about the treatment, but nerve agents attach themselves to certain enzymes in the body. This results in hallucinations and sickness.”

Sergei Skripal remains in the hospital, but his doctors say his condition is “improving rapidly.”

“Although he is recovering more slowly than Yulia, we hope that he, too, will be able to leave hospital in due course,” Blanshard added.

As for Yulia Skripal’s prognosis, Blanshard said, “This is not the end of her treatment but marks a significant milestone.”

The Russian Embassy in London tweeted: “We congratulate Yulia on her recovery. Yet we need urgent proof that what is being done to her is done on her own free will.”

Skripal is thought to be under the protection of British security forces.

The Russian Embassy said it would consider any “secret resettlement” of Sergei and Yulia Skripal “an abduction of the two Russian nationals” or a forced “isolation.” 

British investigators and Prime Minister Theresa May say the Skripals were poisoned by a Novichok-class military-grade nerve agent of the type developed by the Soviet Union and Russia. 

May said Tuesday that she wishes the younger Skripal “the best for her continuing recovery.”

Russian officials have denied wrongdoing in the case. Top Russian diplomats have charged that the attack could have been carried out by British agents, in an attempt to smear Russia, increase military budgets or distract their own people from difficult Brexit negotiations.

After the attacks, 28 countries, including the United States, booted more than 150 Russian diplomats — many suspected of being intelligence agents — from their embassies. Russia responded with a similar number of expulsions.