Sarah Everard died from a compression of the neck, police have said.
A major police investigation was launched and her body was found a week later in woodland in Kent.
The Metropolitan Police said on Tuesday: “A post-mortem examination into the death of Sarah Everard held at the William Harvey Hospital in Ashford has given cause of death as compression of the neck.
“Sarah’s family have been informed and are being supported by specialist officers.”
Serving Metropolitan Police officer Wayne Couzens, 48, from Deal, Kent, has been charged with her kidnap and murder.
A provisional date has been set for his trial in October.