Second Vladimir Putin enemy, a close associate of Boris Berezovsky, found dead in London

UK police are investigating the unexplained death of Russian businessman Nikolai Glushkov in southwest London. Photo / AP

Counter terrorism police have launched an investigation into the 'unexplained' death of a Russian business partner of Boris Berezovsky, Vladimir Putin's arch enemy.

Nikolai Grushkov, 69, was found dead at his home in New Malden in south London on Monday evening.

The Russian newspaper Kommersant has reported that the 68-year-old was found by his daughter and had 'strangulation' marks on his neck.

Grushkov was the closest aide to Berezovsky who died in mysterious circumstances in 2013 at his home in Surrey. The death of Grushkov just eight days after the attempted assassination of Sergei Skripal, the Russian double agent who sold state secrets to MI6, will cause alarm although Scotland Yard has insisted there is no evidence to suggest the two incidents are linked.

Nikolai Grushkov was a close aide to Boris Berezovsky who died in mysterious circumstances in 2013 at his home in Surrey. Photo / Getty

Friends of Berezovsky insist he was murdered on Russian president Putin's order.

The metropolitan Police said in a statement issued yesterday: "An investigation is under way following the death of a man in his 60s in Kingston borough.

"Police were called by the London Ambulance Service at 10.46pm on Monday, 12 March to reports of a man found deceased at a residential address in Clarence Ave, New Malden.

"Officers attended and next of kin have been informed. Whilst we believe we know the identity of the deceased, formal identification is yet to take place.

"A post-mortem examination will be held in due course.

"The death is currently being treated as an unexplained. If there is a change in the status of the investigation, an update will be provided.

"At this stage the Met Police Counter Terrorism Command is leading the investigation as a precaution because of associations that the man is believed to have had.

"There is no evidence to suggest a link to the incident in Salisbury."

Николай Глушков. 1949-2018.

Posted by Damian Kudryavtsev on Tuesday, 13 March 2018

Glushkov left Russia after a Moscow court sentenced him to a two-year suspended sentence for fraud in 2006.

In March last year, he was handed a second eight-year sentence in absentia and a one million Russian Ruble fine for allegedly defrauding Aeroflot of $122 million during his tenure as finance director there in the late 1990s.

Glushkov denied all the charges against him.

In 2016, he told Russian media that Aeroflot was attempting to sue him in a civil case in the High Court in London.