GWENT Police has referred itself to the police watchdog following its response to a missing persons report linked to a fatal crash.

The force took the lead after three women from Newport, and later two men from Cardiff, were declared missing after reportedly attending a club in Maesglas on Friday night.

The group was last seen in the early hours of Saturday morning, and relatives and police officers launched a search for them over the weekend.

On Monday, however, Gwent Police announced the group's car had been found, along with the five members of the group, near a roundabout on the A48 road in St Mellons.

Three of them had been pronounced dead, and two had been taken to hospital with serious injuries.

Two police forces responding to the case

The Argus understands the case is now being handled by both Gwent Police and South Wales Police.

Gwent Police is currently responsible for the missing persons case, while South Wales Police is taking the lead on the crash investigation.

The Gwent force said it said referred itself to the Independent Office for Police Conduct (IOPC) "in line with normal procedures".

Why do police forces refer themselves to the IOPC?

The force would not confirm to the Argus the specific grounds for the referral, but the IOPC website states police forces must refer themselves to the watchdog in certain circumstances.

These include when "certain complaints made to their force, such as those that include an allegation of serious corruption or serious assault".

Forces must also contact the IOPC when there are "indications that police officers or staff have committed misconduct - for example, any suggestion that a criminal offence has been committed or that a serious injury has been caused".

And the watchdog must also receive a referral "if someone had direct or indirect contact with the police when, or shortly before, they were seriously injured or died".

"However, forces only need to refer cases where the contact may have caused or contributed to the death or injury," the IOPC adds in relation to the last criteria.

What did the IOPC say?

An IOPC spokesman said: "We can confirm that Gwent Police have advised us that they are making a referral in connection with this tragic incident and we will carry out an assessment in due course to determine what further action may be required from us."

How you can help the police investigation

Specialist officers are supporting the families of those involved and "enquiries are ongoing", a Gwent Police spokesperson said.

Anyone with any information is asked to call police on 101, or send a direct message on social media, quoting 2300071791.