Wiltshire Police has apologised to the family of Dawn Sturgess for wrongly identifying her condition after her fatal poisoning as an overdose.

Police were acting on the basis that she was a “well-known drug addict” after she was poisoned, an inquiry into her death was told.

Michael Mansfield KC, counsel on behalf of the family of Ms Sturgess and Charlie Rowley, told the inquiry the information was false and “there was no intelligence that Dawn was a drug user”.

He added: “Wiltshire Police now accept that Dawn should not have been characterised as a drug user, and it was an error that she was. Wiltshire Police have apologised to Dawn’s family for their error.

Dawn Sturgess, 44, died after being exposed to the Russian nerve agent which was left in a discarded perfume bottle in Amesbury, Wiltshire, in July 2018.

It followed the attempted murders of former spy Sergei Skripal, his daughter Yulia and then-police officer Nick Bailey, who were poisoned in nearby Salisbury in March that year.

They were poisoned when members of a Russian military intelligence squad are believed to have smeared the nerve agent on Mr Skripal’s door handle.

All three survived, as did Ms Sturgess’s boyfriend, Charlie Rowley, who had unwittingly given her the bottle containing the killer nerve agent.

After her death, Mr Rowley described Ms Sturgess as “a lovely lady, she had a big heart, she’d help anyone if she could” and her mother said Ms Sturgess was “the happiest she’d been for a long time”, the inquiry heard.

Ms Sturgess suffered from long-term alcohol dependence, but in the months before her death was “settled and happy”.

Her family want to understand why doctors initially theorised that her symptoms may have been caused by a drug overdose when she was taken to hospital after coming into contact with Novichok, Mr O’Connor said.

He added that the family wished to know “whether any of the things that may have gone wrong in Dawn’s treatment could have made a difference to her chances of survival”, adding: “To use a legal term – if there were failings, were they causative?”

The inquiry, which is set to continue until December, will also examine whether the poisoning of Ms Sturgess could have been prevented.