The widow of poisoned spy Alexander Litvinenko, Marina, is "utterly dismayed by the coroner's decision to abandon his search for the truth about Russian state responsibility for her husband's death", her solicitor has said.
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Explosives experts were called to the nuclear reprocessing site in Cumbria, to help deal with chemical substances.
The arrests were made on suspicion of producing and disseminating pedophilia content on the internet, the country's Justice Ministry said.
The A4-sized sketch originally went for £75 when it was first sold.