The police watchdog has launched an independent investigation into whether Metropolitan Police officers responded appropriately to a report of indecent exposure following referrals linked to the arrest of a serving officer in the Sarah Everard case.

The Independent Office for Police Conduct (IOPC) said the investigation followed a conduct referral from the Metropolitan Police (MPS) in relation to two officers, received on Wednesday.

The watchdog said the referral was linked to another four, “all connected to the arrest of a serving MPS officer on suspicion of kidnap, murder and a separate allegation of indecent exposure”.

In a statement, the IOPC said: “Our investigation will look at the actions of the MPS after police received a report on February 28 that a man had exposed himself at a fast food restaurant in South London.

“On Wednesday we determined that two conduct referrals relating to kidnap/murder and indecent exposure allegations against the arrested officer should remain under local investigation by the force.

“We are still assessing a mandatory referral in relation to the actions of police after they received a report that Sarah Everard was missing.”

The IOPC added a mandatory referral was received from the Met on Thursday in relation to police contact with the arrested officer who was treated in hospital after sustaining a head injury while in custody on Wednesday, which is being assessed to determine what further action may be required.

The Met Police said it had made a voluntary referral to the IOPC “for a conduct matter in relation to the police investigation into the separate allegations of indecent exposure”, which is being investigated by the watchdog.

The force also made a mandatory referral to the IOPC over the “actions of police” after Sarah Everard was reported missing.

Another mandatory referral has been made by the force over the arrested man being taken to hospital for treatment to a head wound sustained in custody.

The Met said the suspect was “being monitored by CCTV and received immediate first aid” and they await the IOPC’s assessment.

The Met Police also confirmed it had made two referrals – one voluntary and one mandatory – to the IOPC “linked to the conduct of the officer arrested on suspicion of kidnap, murder and indecent exposure,” which are being investigated locally.

The force said it was “offering every assistance” to the IOPC.

Earlier Scotland Yard revealed that the police officer arrested on suspicion of Sarah’s murder remains in custody at a London police station after an application to extend his detention was granted at Wimbledon Magistrates’ Court.

And a statement released on behalf of Sarah's family by the Metropolitan Police appealed for information to help the force’s investigation.

Sarah's family said: “Our beautiful daughter Sarah was taken from us and we are appealing for any information that will help to solve this terrible crime."