The police watchdog is to supervise an investigation over the case of a couple whose bodies went undiscovered under a landslip in Dorset for more than a week.
Rosemary Snell and Michael Rolfe, from Somerset, were found in a car at the partially-collapsed Beaminster Tunnel.
The Independent Police Complaints Commission (IPCC) will now oversee an Avon and Somerset Police investigation.
The IPCC has said it is happy with the way Dorset police handled the case.
Ms Snell and Mr Rolfe went missing on 7 July but it was not until 16 July that Avon and Somerset police alerted their colleagues in Dorset that the couple had been traced to the Beaminster area.
The vehicle, a silver Skoda, is believed to have been buried for more than a week.
The A3066 road, which runs through the tunnel, has been closed since the landslide.