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Berezovsky death: Chemical hazard police search house

24 March 2013 Last updated at 07:03 GMT

Police with expertise in environments contaminated with chemical, biological and nuclear material have been involved in a search of the house of the late Boris Berezovsky.

The exiled Russian tycoon, aged 67, was found dead on Saturday, and a Thames Valley police cordon remains in place as police investigate his unexplained death.

Bridget Kendall reports.