LONDON (AP) — British police say no sign of forced entry has been found at the home where a London-based Russian businessman died from a neck compression.

Metropolitan Police Commander Clarke Jarrett said Monday the forensic investigation into the death of businessman Nikolai Glushkov is continuing. Glushkov, 68, was found dead at his south London home on March 12.

The 68-year-old Glushkov was an associate of Boris Berezovsky, a Kremlin critic who died under disputed circumstances in 2013.

Police have said they do not see a link between the Glushkov case and the recent poisoning of an ex-spy and his daughter in the English city of Salisbury.