The decontamination of Sergei Skripal's home in Salisbury is underway, Wiltshire Council has confirmed.
The move is part of a schedule of ongoing work to make Salisbury and Amesbury safe for residents and visitors.
It comes as Russia faces a fresh wave of international condemnation over the Salisbury spy poisoning. Moscow was accused of “playing dice” with the lives of people living in Wiltshire by the UK during an emergency debate at the United Nations.
Sergei Skripal and his daughter, Yulia, became ill after coming in contact with the nerve agent Novichok.
A cordon is in place so that police investigations or clean-up work can be carried out safely. It will remain in place until the decontamination has been completed.
Counter-terrorism officers believe the house is where Mr Skripal, a former Russian agent, and his daughter Yulia were contaminated with nerve agent on the 4th of March, after a high concentration of the chemical weapon was found on the front door.
The two men alleged to have been behind the March poisoning - Alexander Petrov and Ruslan Boshirov - have been identified by the UK as members of the GRU, Russia's military intelligence service.
The Skripals were left critically ill after exposed to the military grade nerve agent, but were later released from hospital.
The work is being planned and overseen by Defra in partnership with Wiltshire Council and carried out by specialist military teams.