British police with expertise in environments contaminated with chemical, biological and nuclear material are searching the house of the late exiled Russian tycoon Boris Berezovsky.
Boris Berezovsky, 67, was found dead on Saturday, and a Thames Valley police cordon remains in place as police investigate his unexplained death.
His body remains at the Berkshire house while the search – described as a precaution – takes place, police said.
They say local people are not at risk.
The ambulance service was called to the Ascot house of Boris Berezovsky at 15:18 GMT on Saturday. His body was reportedly found in a bath.
A Thames Valley police update said: “Specially trained officers are currently at the scene, including CBRN [chemical, biological, radiological, and nuclear] trained officers, who are conducting a number of searches as a precaution.
“This is to enable officers to carry out an investigation into the man’s death.”
Supt Stuart Greenfield said: “We are aware the cordon is causing disruption to local residents and we apologize for any inconvenience, but it is important we take all necessary measures to ensure a full and thorough investigation can be carried out.
“I would like to reassure residents that we are confident there is no risk to the wider community.”
He said the property was part of a large estate, so a number of roads were closed “and will remain so for the time being”.
Boris Berezovsky was a wanted man in Russia, an opponent of President Vladimir Putin, and had survived numerous assassination attempts, including a bomb that decapitated his chauffeur. He emigrated to the UK in 2000.
The Russian tycoon was a close friend of murdered Russian émigré and former KGB officer Alexander Litvinenko, who died in 2006 after he was poisoned with the radioactive material polonium-210 while drinking tea at a London meeting.
Without naming Boris Berezovsky, the Kremlin has accused its foreign-based opponents of organizing the assassination – a claim Boris Berezovsky denied. He accused Vladimir Putin of being behind the death.
In the interview with a journalist from Forbes magazine on Friday, Boris Berezovsky said that he had changed his mind on many things, his life no longer made sense and he wished he could return to Russia.
Last night a Kremlin spokesman said that Boris Berezovsky had recently written to Vladimir Putin, saying he wanted to go home.
Boris Berezovsky’s wealth is thought to have considerably diminished in recent years, leaving him struggling to pay debts in the wake of costly court cases.
Last year, Boris Berezovsky lost a £3 billion ($4.7 billion) damages claim against Chelsea Football Club owner Roman Abramovich.