Suspects in Attack on Ex-Spy Are in Russia, UK Newspaper Reports

LONDON — The British police have identified suspects in the nerve agent attack on a former Russian spy and his daughter, and the suspects are believed to be in Russia, the newspaper The Daily Telegraph has reported, citing unnamed security officials.

Investigators have settled on “persons of interest” by scanning passengers on flights in and out of Britain, the newspaper reported. They have also gathered information from surveillance footage in the town of Salisbury, England, where the crime occurred, by zeroing in on car license plates.

A spokeswoman for the Metropolitan Police would not comment on the report, saying only that the police “are not discussing specific lines of inquiry.”

The investigation began on March 4 when the former spy, Sergei V. Skripal and his daughter, Yulia, collapsed convulsing and vomiting on a bench in Salisbury.

Police officers reporting to the scene first thought it was a drug overdose. But after learning Skripal’s identity, scientists at a nearby chemical weapons laboratory were able to identify the poison as Novichok, a lethal nerve agent developed in the last years of the Soviet Union. Skripal, who had served as a double agent for British intelligence, was released from prison in an exchange for 10 Russian agents unmasked in the United States.

British authorities have said it is “highly likely” that the Skripals were poisoned on orders of Russian officials, perhaps as a lesson to other potential defectors.

Officials in Moscow have denied any involvement in the attack, noting how little evidence British officials have brought forward.

If officials in Britain have indeed identified suspects, it is highly unlikely that Russia would agree to extradite them. A few weeks after the death of Alexander V. Litvinenko, a former officer in the Federal Security Service, or FSB, a British officials asked to speak to five suspects living in Russia. But their Russian counterparts said they could only be questioned or tried in Russia.

Five months later, the British Foreign Office formally requested the extradition of Andrei K. Lugovoi to face charges in Litvinenko’s death, and the Russian prosecutor declined, arguing that Russia had not been able to review the evidence, and that Russia’s Constitution prohibited the extradition of citizens.