Salisbury Novichok attacks: Suspects tracked using phone data

Commander Dominic Murphy from counter terror policing, gave evidence on Tuesday morning, saying Operation Caterva was “a small team based on need-to-know” and was rated “top secret”.

Police worked closely with MI5 agents and the wider intelligence community, he said.

Charges against the Russians were under their alias names, so that is how they are being referred to in the inquiry.

Petrov and Boshirov were members of the Russian intelligence unit known as the GRU, said Commander Murphy.

“They were particularly of one unit within the GRU called 29155, and it was within that role that they undertook this incident [in Salisbury],” he added.

The trio were charged with conspiracy to murder, three counts of attempted murder, two counts of grievous bodily harm with intent, and one count of use or possession of a chemical weapon.

Those charges relate to the events in Salisbury in March 2018, not the subsequent death of Ms Sturgess after she came into contact with Novichok in Amesbury a few months later.