Police cordoned off Berezovsky's home in Ascot, Berkshire following his unexplained death and launched an investigation. In the early stages of the investigation reports claimed that he was found dead in his bath, by a bodyguard. It has since been revealed Boris was found dead on his bathroom floor.
Early Sunday, in the U.K. police sealed off Berezovsky's property and checked it for hazards. They stressed this was a precautionary measure and reassured neighbors they were not at risk. Chemical and radiation experts assisted the police.
Sky News reported Sunday a police statement as saying "Specially trained officers are currently at the scene, including Chemical, Biological, Radiological and Nuclear (CBRN) trained officers, who are carrying out a number of searches as a precaution. "The body of the man is still in the property at this time."
So, why the chemical and radiation checks? Former Moscow agent Alexander Litvinenko was killed by Polonium-210 poison in London in 2006. The killer is unknown but some in the media accused Berezovsky. He fought and won a court case to clear his name in 2010 but there are recent allegations online.
CNN reported Sunday "Berezovsky, a fierce critic of Russian President Vladimir Putin, blamed the Kremlin for the 2006 death of former Russian spy Alexander Litvinenko, who died after being poisoned by the radioactive material polonium-210. In a deathbed statement, Litvinenko blamed Putin, an accusation the Kremlin strongly denied. For years, Berezovsky bankrolled the effort of Litvinenko's widow to push for an inquest into her husband's death".
Boris denied any involvement in Litvinenko's death claiming the two men were kindred-spirits, once both were living in exile.
Berezovsky was one of the so-called Russian Oligarchs. He was a powerful man in Yeltsin's Russia building up a large fortune, at a time when ordinary Russians' incomes dropped. In recent years in Britain his wealth has declined. He lost a costly court case against Chelsea Football Club owner Roman Abramovich, in 2012.
The court case allegedly left Boris a broken man. There were soon reports that he was suffering depression, yearned to return to Russia and that his death was suicide.
On Sunday police announced the Berkshire mansion of Mr Berezovsky safe. No evidence of biological, nuclear or radioactive contamination was found during the extensive search. Although some in Russia were already reporting that Berezovsky committed suicide, British police issued no confirmation of the cause of death.
Tuesday it was revealed that Berezovsky was found on the floor of his bathroom, with injuries consistent with hanging. A post-mortem examination, autopsy, found hanging injuries.
MSN News reports Detective Chief Inspector Kevin Brown saying: "Scenes of crime officers are carrying out further forensic examinations at the property and these are expected to last several days. "A cordon will remain in place until this work has been completed, to protect the scene. While this important investigative work continues, we are unable to comment on any items found within the property. I would like to reiterate that we have no evidence of any third-party involvement at this stage."
Chemical experts joined the investigation after the paramedic who pronounced Boris dead at the scene raised a radiation alarm. As the paramedic left Berezovsky's property a radiation detector he was wearing sounded an alarm.
Thursday an inquest into his death opened. The inquest heard that Boris was found dead on the bathroom floor, with a ligature round his neck, He had injuries consistent with hanging. The inquest was soon adjourned however until investigations are complete.
There are still many unanswered questions. Speculation is bound to follow. Was a third-party involved in the death of Berezovsky? Was it really suicide, or was it murder? Will it be one of those cases which is never truly resolved?
Updates will follow in due course.