The woman’s next of kin have been informed, the Met said.
Det Ch Supt Trevor Lawry said: “My heart goes out to the woman’s family and friends who have lost their loved ones in these tragic circumstances.”
Two officers who were in the unmarked car were also taken to hospital following the collision, and have since been discharged.
Det Ch Supt Lawry said an investigation was under way and the incident had been referred to the police watchdog, the Independent Office of Police Conduct (IOPC).
A spokesperson for the IOPC confirmed they were investigating the incident.
