LONDON — The lead counsel for a public inquiry into the 2018 death of a British woman poisoned by a Soviet-developed nerve agent said Monday that there was enough poison in the vial she unwittingly opened to kill thousands of people.

Dawn Sturgess and her partner collapsed after they came into contact with a discarded perfume bottle containing the nerve agent Novichok in the southwest England town of Amesbury. She had sprayed the contents of the bottle on her wrist and died days later. Her partner survived.

“The evidence will suggest that this bottle — which we shall hear contained enough poison to kill thousands of people — must earlier have been left somewhere in a public place creating the obvious risk that someone would find it and take it home,” lead counsel Andrew O’Connor said.

Their exposure came four months after a former Russian intelligence officer, Sergei Skripal, and his daughter were sickened by Novichok in an attack in the nearby city of Salisbury.

Britain has blamed Russian intelligence, but Moscow has denied any role. Russian President Vladimir Putin called Skripal, a double agent for the United Kingdom during his espionage days, a “scumbag” of no interest to the Kremlin because he was exchanged in a spy swap in 2010.

The Skripals won’t testify during the inquiry out of fear for their safety.

But in a witness statement to the inquiry, Skripal said that the attack was a shock because it was “not honorable” to kill people who had been exchanged.

“I had received a presidential pardon and was a free man with no convictions under Russian law. I never thought the Russian regime would try to murder me in Great Britain,” Skripal said in a statement read by O’Connor. “They could have killed me easily if they wanted to when I was in prison.”

He said he believed that Putin “must have at least given permission for the attack.”

“I believe Putin makes all important decisions himself,” his statement said.

Heather Hallett, the coroner who held the 2018 inquest into Sturgess’ death, said that a public inquiry was needed to conduct a complete look at how the woman died. Unlike inquests, which are routinely held in cases when the cause of death is unknown or if someone dies violently, public inquiries are allowed to consider sensitive intelligence material.