A public inquiry hearing took place in London on Monday into the 2018 death of a British woman after exposure to a Soviet-developed nerve agent.

The amount of Novichok in a perfume bottle in Amesbury, southwestern England that killed Dawn Sturgess was enough to kill thousands of people, the counsel to the inquiry said.

Andrew O'Connor opened the proceedings by describing Sturgess as an innocent member of the public who had been caught in the "crossfire of an illegal and outrageous international assassination attempt.”

"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," he said.

Michael Mansfield, counsel on behalf of Sturgess' family, told the hearing that local police were forced to rely on Wikipedia for information on how to respond to the poisonings.

"Was there a failure to prevent a chemical weapons attack on UK soil? Were countless members of the public put at risk, with the potential for hundreds or even thousands of deaths?" he asked.

Strurgess’ death came four months after Sergei Skripal, a former Russian agent who settled in Britain, and his daughter were sickened by the same nerve agent in an attack in Salisbury, a nearby city.

Skripal blamed the attack on Russian President Vladimir Putin, saying that before he "never thought the Russian regime would try to murder me in Great Britain."

Russia has denied any involvement.

The inquiry to establish the circumstances of Sturgess’ death is expected to last into December.

Sturgess died in hospital on July 8, 2018 after she was exposed to Novichok, which had been stored in a discarded perfume bottle found by her husband and given to her as a gift.

Her death followed the attempted murders of Skripal, his daughter, Yulia, and ex-police officer Nick Bailey, who were poisoned in Salisbury that March.