Special chemical and nuclear experts have been called in to conduct precautionary searches, as police investigate the death of Boris Berezovsky.

His body was found in a house in Berkshire, England.

It has reported that he took his own life but detectives are treating it as "unexplained" until they establish exactly what happened.

In 2009, Berezovsky explained why he was considered an enemy by Russia's President Vladimir Putin, fiercely criticisng the regime.