A murder inquiry has been launched by counter-terrorism police investigating the death of a Russian exile who was friends with a critic of Vladimir Putin.

Police announced the news after a post mortem confirmed businessman Nikolay Glushkov died from “compression to the neck”, on Friday.

Glushkov’s death was initially treated as unexplained after he was found dead by family and friends at his New Malden home, in London, on Monday. 

Counter-terrorism police were called in as a precaution, given the death occurred in the wake of the poisoning of former Russian spy, Sergei Skripal, 66, and his 33-year-old daughter, Yulia, in Sailsbury, earlier this month. 

“At this stage there is nothing to suggest any link to the attempted murders in Salisbury, nor any evidence that he was poisoned,” the Met said. 

Glushkov’s family had been informed of the development, police said, adding that counter-terrorism police would continue to run the investigation. 

“As a precaution, the command is retaining primacy for the investigation because of the associations Mr Glushkov is believed to have had,” the Met said.

“There are no wider public health concerns in relation to this investigation.”

Glushkov, a retired financial director, was a Russian national who had lived on Clarence Avenue for two years. He was friends with the late oligarch Boris Berezovsky, who famously fell out with Putin. 

Earlier this week multiple media reports suggested Glushkov’s daughter Natalia, who is studying in London, had gone into hiding. 

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

In 2017, during a trial in absentia in Russia, Glushkov was sentenced to eight years in prison for stealing $123m from his former employer, Aeroflot.

The Metro reported that Glushkov’s debt has been passed on to Natalia and her older brother, Dmitry.

The newspaper quoted a representative of Russia’s Bailiff Service as saying: “After receiving confirmed information about the death of the debtor, the bailiff will replace him with his legal successors.”

Berezovsky was found dead in March 2013 at his ex-wife’s home in Berkshire. His death was not treated as suspicious, but his friends were not convinced and a coroner later recorded an open verdict. 

Detectives are “retaining an open mind” about the Glushkov case, police said, and urge anyone with information that will assist the investigation to contact them in confidence on 0800 789 321.

“In particular” police are appealing for anyone who may have seen or heard anything suspicious at or near Glushkov’s home between Sunday 11 March and Monday 12 March.

A blue and a purple tent remained covering the front drive of Glushkov’s home on Friday, which is cordoned off along with several adjoining properties either side.

Kate Fitzsimmons, who lives opposite Glushkov, said she had never spoken to him but he would wave at her from across the road.

Asked if he seemed friendly, the 87-year-old said: “I thought so. I thought he was just an ordinary friendly Englishman really. I didn’t know he was Russian.”

She said it was “very sad” that a murder investigation had been launched, adding: “Well there’s nothing one can do about it is there, really?”

Fitzsimmons spoke of her shock at returning to her home early on Tuesday morning to all the police activity.

She said: “(It was) a great big shock, yes, I was really very shocked actually.

“I’m a nurse, I don’t get shocked easily, but it did you know sort of shock me and I was at a meeting at the church until half past ten two nights ago and they walked me home, which was kind of them.”