Twelve people have been arrested as part of a major investigation into the criminal activity allegedly linked to the events that ended with the deaths of two police officers and five other people in a horrific crash on the A66.

Cleveland Police said nine men and three women had been detained as detectives continued investigating what happened in the hours leading up to the fatal collision near Middlesbrough.

The arrests mark a significant development in the investigation, which has now expanded beyond the circumstances of the crash itself to include allegations of serious and organised criminal activity.

PC Matthew Blades, 37, and PC Tom Clough, 38, were killed when a Volkswagen Passat travelling on the wrong side of the A66 collided head-on with their marked armed response vehicle.

The five men inside the Passat were also killed.

They were aged between 17 and 23 and were pronounced dead at the scene.

Police have previously said the Passat was involved in a pursuit before the collision, although the officers who died were not part of that initial pursuit.

The latest arrests involve suspects aged between 19 and 61.

According to Cleveland Police, the 12 people have been arrested on suspicion of a range of offences.

Four were arrested on suspicion of participating in an organised crime group.

A further four were arrested on suspicion of possessing a firearm.

Four suspects were also arrested on suspicion of possessing class A and class B drugs with intent to supply.

The arrests form part of what police described as a “wide-scale investigation into the criminality which took place” before the fatal crash.

Officers from Durham, Northumbria and North Yorkshire police forces have assisted Cleveland Police with the investigation.

Authorities have also identified and recovered a Volvo XC60 which they believe was associated with activities involving people connected to the Volkswagen Passat.

The discovery of the vehicle is another strand of an investigation that has rapidly grown in scope since the fatal collision.

Police have previously said that some of the five men who died may have had links to serious and organised criminal activity.

They have also confirmed that four of the five had previous convictions.

The allegations do not mean that the five men were responsible for all of the criminal activity now being investigated, and detectives have stressed that their wider investigation is ongoing.

The latest arrests concern living suspects and are based on allegations that must still be investigated and tested through the criminal justice system.

Assistant Chief Constable Wayne Fox described the operation as a fast-moving and complex investigation with significant links to serious and organised crime.

He said police had a responsibility to investigate the criminal activity that led up to the tragedy and pursue those who may have been responsible.

“We have a duty to respond to, and thoroughly investigate, the serious criminal activity that resulted in this fatal incident, and to bring all those responsible to justice,” Fox said.

He also praised Cleveland Police officers and staff for continuing their work despite the loss of two colleagues.

The deaths of Blades and Clough have had a profound impact on the force and the wider community.

Both officers were on duty when they were killed.

Their families have paid emotional tributes to the men, describing them as devoted family members and dedicated police officers.

PC Blades was a husband and father of two young boys.

His widow described him as her beloved husband, best friend and a devoted father, saying his children would grow up knowing what an incredible father he had been.

PC Clough’s family remembered him as a hero with a fantastic sense of humour who was always willing to help others.

More than £500,000 has now reportedly been raised for the families of the two officers.

Floral tributes have also been placed close to the A66 crash site.

One tribute poignantly reminded those passing the scene that behind every police uniform is a person with a family, friends and people whose lives they have touched.

The investigation has also reignited a wider debate over dangerous driving videos shared online.

At least one of the young men killed in the crash had previously posted footage appearing to show reckless driving.

The material has raised concerns about a social media culture in which dangerous driving can attract attention, followers and potentially financial rewards.

Police have stressed, however, that there is currently no evidence that the activities filmed on the night of the A66 tragedy were specifically carried out for TikTok.

That distinction has become important as authorities attempt to separate established evidence from speculation following the crash.

Prime Minister Andy Burnham described the wider social media trend involving dangerous driving as “truly reprehensible”.

Culture Secretary Lisa Nandy has called for assurances from technology companies and Ofcom that dangerous content is being actively identified and removed.

She has argued that social media platforms should not allow material encouraging dangerous behaviour to remain available simply because it attracts large audiences.

The issue has also been raised by Defence Minister Luke Pollard.

Speaking to BBC Radio 5 Live, Pollard said social media companies needed to “step up” and help ensure that the internet does not reward dangerous behaviour with views, attention and financial incentives.

His comments came as investigators continued trying to establish exactly what happened before the A66 crash.

The concern about online driving content has been intensified by the discovery of older footage apparently showing reckless behaviour.

The Guardian identified a YouTube video that had been viewed around 2.5 million times and appeared to show a Honda being driven at dangerous speed through a council estate before travelling along a narrow country road.

Google, which owns YouTube, terminated the account after being approached for comment.

The existence of such material has prompted renewed questions about how easily dangerous driving content can spread online.

Critics argue that videos showing reckless behaviour can normalize dangerous driving and encourage others to imitate what they see.

The debate has taken on added urgency because the A66 crash occurred only days after another devastating road tragedy in Ireland.

Earlier this month, five young men died after the vehicle they were travelling in was driven the wrong way along the M9 motorway.

Four other people were injured in that collision.

The similarities between the two incidents have intensified concern about reckless driving and the influence of social media.

However, investigators in the Cleveland case continue to focus on evidence rather than assumptions about any online trend.

The central investigation remains the circumstances surrounding the Volkswagen Passat, the police pursuit and the events immediately before it collided with the officers’ vehicle.

Detectives are also examining the alleged organised criminal activity now linked to the wider investigation.

The recovery of the Volvo XC60 could prove significant as officers attempt to reconstruct movements and connections between people and vehicles.

The arrests involving alleged firearms and drug offences suggest investigators are examining activity beyond the fatal collision itself.

Police have not said whether the 12 people arrested are directly connected to the moment of impact or whether some are being investigated for separate offences discovered during the wider inquiry.

That distinction may become clearer as the investigation develops.

For Cleveland Police, the operation is now likely to continue for weeks or months.

Assistant Chief Constable Fox said the force would maintain what he called a robust response against people who seek to cause harm to local communities.

He also thanked members of the public and police forces across the region for their support following the deaths.

The loss of Blades and Clough has made the investigation particularly painful for colleagues.

Yet officers have continued working to establish what happened, even as they mourned two members of their own force.

The latest arrests demonstrate how far the investigation has expanded since the early hours of the crash.

What initially appeared to be a devastating road collision is now being investigated alongside allegations involving organised crime, firearms and drugs.

At the same time, questions remain over the role of dangerous driving footage and social media in encouraging reckless behaviour.

For the families of the seven people who died, however, the consequences are already permanent.

Two police officers who went to work to protect the public never returned home.

Five young men also lost their lives in the same catastrophic collision.

As detectives continue examining the events leading up to the crash, the 12 arrests represent only one stage of a much larger investigation.

Police have made clear that their work is not finished.

Those responsible for any criminal offences uncovered during the inquiry could yet face further action, while investigators continue piecing together the chain of events that led to one of the most devastating crashes in the region in recent years.