ABC News July 18, 2018

Chemical weapons experts join Novichok investigation after UK couple poisoned

WATCH: Woman sickened by nerve agent Novichok in England dies: UK police

The Organization for the Prohibition of Chemical Weapons (OPCW) has sent a team to help the British investigation into the latest exposure of Novichok in Amesbury, Wiltshire.

The OPCW said it collected samples of the substance, believed to be a Novichok nerve agent, which were already in the process of being to sent to laboratories for independent study.

Wiltshire police in England are searching Salisbury’s Queen Elizabeth Gardens as part of the ongoing investigation into the Novichok contamination that killed a British woman and seriously injured her partner.

The gardens have been closed off to the public for two weeks since Dawn Sturgess and her partner, Charlie Rowley, fell ill following exposure to a Novichok nerve agent in late June, four months after the poisoning of former Russian spy Sergei Skripal and his daughter Yulia Skripal.

“The commencement of the searching of the gardens is a significant step in the operation,” Wiltshire Police Deputy Chief Constable Paul Mills said.

He added, “We are intentionally undertaking a detailed and meticulous search so that the public can return to using the gardens with confidence when they are reopened.”

(MORE: Search widens for source of deadly nerve agent that has town on edge)

A murder inquiry was launched after Sturgess died at a local hospital on July 8. She was at Rowley's house in Amesbury, located just several miles away from Salisbury, when she first fell ill.

Facebook/Metropolitan Police/AFP/Getty Images
A combination of undated pictures of Dawn Sturgess and Charles Rowley.

Investigators are studying whether the British couple's poisoning is linked to the Skripals.

Around 100 detectives are supporting the regional police force working on the case.

Rowley remains in the hospital and told his brother he was “devastated” when he learned of Sturgess’ death.