Police investigating the murder of the Russian businessman Nikolai Glushkov say they have found no evidence of forced entry into his home in New Malden, south-west London.

On Monday, officers launched fresh house-to-house inquiries in the neighbourhood.

The 68-year-old was found dead at the property on Clarence Avenue on 12 March and a postmortem showed he had died from compression to the neck, suggesting he was strangled. Police ruled out suicide and launched a murder investigation on Friday.

Detectives are focusing on what happened in the immediate area on Sunday 11 March and Monday 12 March, and are appealing for anyone who may have seen or heard anything suspicious at or near Glushkov’s home to come forward.

“I would urge anybody who may have information to get in touch if they have not already done so,” said Commander Clarke Jarrett, the head of the Metropolitan police’s counter-terrorism command, which is running the investigation because of the associations Glushkov is believed to have had.

“We will have officers in Mr Glushkov’s local neighbourhood today, so please come and speak to us if you think you may have seen or heard anything suspicious last Sunday or Monday.”

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

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 the Russian president 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 had killed himself but a coroner recorded an open verdict.

The killing of Glushkov came a week after the attempted murders of Sergei Skripal, a former Russian intelligence officer living in Salisbury, Wiltshire, and his daughter Yulia Skripal, using the nerve agent novichok. The pair remain in a critical condition.

“The investigation is progressing,” said Jarrett. “We have taken a number of statements and have over 400 exhibits which are being processed. We have found no sign of forced entry thus far, but the forensic examination at Mr Glushkov’s home continues and we expect to be there for some time.

“I must stress that there is nothing we have found in our investigation so far to suggest any link to the attempted murders in Salisbury, and I would like to reassure the public in New Malden that there are no wider public health concerns in relation to this investigation.”

There have been no arrests so far.