The family of the murdered Russian businessman Nikolai Glushkov have said they are devastated at his death and are helping counter-terrorism detectives with the investigation.

The 68-year-old was found dead at his home in New Malden, south-west London, on 12 March and a postmortem showed he died from compression to the neck, suggesting he was strangled. Police ruled out suicide and launched a murder investigation last Friday.

“We, the family of Mr Nikolay Glushkov, are very grateful for the messages of sympathy received,” his relatives said in a statement issued through the Metropolitan police, using an alternative spelling of his first name. “A special thank you goes out to the Metropolitan police and the emergency services for their rapid response and assistance on the night.

“We are devastated at the loss of Nikolay and are coming to terms with our grief. We are assisting the counter-terror command with their investigation. As a result we will not be making or releasing any further public statements at this stage of the investigation.”

Detectives have appealed for any footage or images that motorists or cyclists may have captured on dashcams or headcams in Clarence Avenue on Sunday 11 March or Monday 12 March.

At the time of his death, Glushkov was about to defend himself against a fraud claim brought by the Russian airline Aeroflot at the commercial court in London.

In 2017, during a trial in absentia in Russia, he was sentenced to eight years in prison for stealing $123m (£87m) from the airline, which then pursued the case in London. Glushkov failed to arrive at court in central London on 12 March and his body was discovered that evening.

He was a friend of the oligarch Boris Berezovsky, a critic of Vladimir Putin who had clashed in court with Roman Abramovich. Berezovsky was found hanged at his ex-wife’s home in Berkshire in 2013. Police said they believed he killed himself but a coroner recorded an open verdict.

Police have said that at this stage there is nothing to suggest any link to the attempted murders of Sergei and Yulia Skripal in Salisbury this month, nor any evidence that Glushkov was poisoned.

“Detectives are retaining an open mind and are also appealing for anyone with information that could assist the investigation into Mr Glushkov’s murder to contact them in confidence,” Scotland Yard said.