Following the deaths of two boys in Cardiff, gross misconduct notices were issued to two police officers.
On May 22, an accident on Snowden Road in Ely resulted in the deaths of Harvey Evans, 15, and Kyrees Sullivan, 16.
CCTV footage from the time leading up to the event showed a police van pursuing the victims, who were riding an electric bike.
Following reports that they were being chased, the scene descended into violence. Officers were targeted by pyrotechnics and other projectiles, resulting in 15 injuries.
As a result, South Wales Police referred itself to the Independent Office for Police Conduct (IOPC).
In their latest update on the case today, the watchdog confirmed the officers in the vehicle have been served gross misconduct notices.
IOPC said the serving of the notices did not mean disciplinary proceedings would then follow.
It had previously said it was looking at the nature of the interaction with the two boys prior to the crash and the appropriateness of the police officers’ decisions and actions, whether at any time the decisions and actions of the officers in the police vehicle constituted a pursuit and whether the interaction between the police officers and the boys was reported appropriately by the officers prior to and following the collision.
IOPC director David Ford: ‘I wish to again extend my sympathies to the family and friends of Kyrees and Harvey, and to everyone who has felt the impactful loss of two young lives in Ely.
‘The response from the community in helping our investigators has been very positive and I am extremely grateful for this assistance.
‘In case there are still people with relevant information we have yet to speak to, we have placed witness appeal boards in the vicinity of the incident.
‘We would urge anyone who believes they have useful information to come forward to us.
‘We have also met with local community leaders and elected officials to explain our role and the remit of our investigation.
‘As our investigation continues to progress, I would like to reassure everyone that we are focused on establishing precisely what happened in the run-up to the tragic incident.
‘Our work will remain impartial and completely independent of the police.’
Investigators are still reviewing hundreds of video clips and have also reviewed initial accounts and body-worn video from police officers and staff.
As part of the probe into the aftermath, 20 people have so far been arrested in connection with the riot.
South Wales Police said 17 males and three females, aged between 14 and 36, had been arrested on suspicion of riot.
All have since been released on police bail while the investigation continues, the force said.