Five more people, including a 16-year-old boy, have been arrested by detectives investigating the events leading up to the crash on the A66 which left two police officers and five others dead, Cleveland Police said.
Overnight officers continued to disrupt those suspected of being involved in serious and organised crime with five further arrests, taking the total to 17.
The activity has been led by Cleveland Police and supported by the National Crime Agency (NCA) and the North East Regional Organised Crime Unit (NEROCU).
Investigation links to serious and organised crime
Assistant Chief Constable Wayne Fox, responsible for the strategic leadership of the investigation, said: "This has been a fast moving and complex investigation, with significant links to serious and organised criminal activity.
"The events of that tragic night will have a lasting and profound impact on the Cleveland area and the communities we seek to protect."
"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.
"Our robust response will continue in the weeks and months to come, as we continue to tackle those that seek to cause harm to our communities and tackle serious and organised crime."
Police resilience and public support
"Officers and staff across Cleveland have shown incredible resilience in continuing their work in the face of tragedy.
"Two of their colleagues lost their lives while serving the people of Cleveland and, while the impact will be felt by our people for a long time to come, they have continued to act with the upmost professionalism.
"I am also extremely grateful for the support we have received, and continue to receive, from the public of Cleveland and our wider police family."
The updates on the 12 arrests issued yesterday (Monday 24 August) are below.
