Police were called shortly before 5.30pm on Monday after a grey Citroen DS9, a white Ford Transit van and a DAF cattle transporter truck and trailer collided on the A354 Salisbury Road at East Woodyates.

The boy, from Hampshire, was a passenger in the Citroen. He died at the scene and his family has been informed.

The driver of the Citroen - a woman in her 30s from Hampshire - has been arrested on suspicion of murder and a driving offence, Dorset Police said.

She was taken to hospital to be treated for her injuries and remains in police custody, the force added.

Detective Chief Inspector Neil Third said a "detailed scene examination was carried out overnight" and "initial lines of enquiry" have been completed.

He added: "I would ask any witnesses who have not already spoken to police, or anyone who may have captured relevant dashcam footage, to please come forward.

"Also, I am keen to speak to anyone who may have seen the manner of driving of any of the vehicles involved prior to the incident."