Updated

British police say that experts in hazardous materials are searching a property after the death of Boris Berezovsky, the self-exiled Russian tycoon who had a bitter falling out with Russian President Vladimir Putin.

Police say a 67-year-old "believed to be" Berezovsky was found dead at the property in Ascot, a town 40 kilometers (25 miles) west of London on Saturday. Thames Valley police say his death is being treated as "unexplained."

They said Sunday they have set up a cordon and that officers are conducting the search "as a precaution" and there is no risk to neighbors. The BBC described the site as Berezovsky's home.

In recent years, the one-time Kremlin powerbroker-turned-thorn in Putin's side fended off legal attacks that often bore political undertones — and bit into his fortune.