A Russian exile who was close friends with the late oligarch Boris Berezovsky has been found dead in his London home, according to friends.
Nikolai Glushkov was discovered by his family and friends late on Monday night, aged 68. The cause of death is not yet clear. One of his friends, the newspaper editor Damian Kudryavtsev
There may be nothing suspicious about the death of Nikolai Glushkov, but given the current context it is impossible for the police to do anything other than take it seriously and ask Counter Terrorism Command to lead the investigation. In the past, there has been criticism of the police not taking such deaths seriously enough.
The Home Secretary has also today asked the police and MI5 to review a series of other deaths of Russians and Russian-linked individuals in the UK over the last decade or so.
One of those may well be Boris Berezovsky, who was found dead in 2013 and who was a close ally of Glushkov. This is all a sign that the prism through which those past deaths are seen has changed. That is because the notion of what Russia might be capable of doing has changed.
The top priority though, for MI5 and police, will not be looking back at previous cases but instead the ongoing investigation in Salisbury.
AnalysisBy BBC security correspondent Gordon CoreraThere may be nothing suspicious about the death of Nikolai Glushkov, but given the current context it is impossible for the police to do anything other than take it seriously and ask Counter Terroris