ONE lane of the A419 is back open with one lane remaining closed following the horrific crash this morning.

A 30-year-old man is in Oxford's John Radcliffe Hospital with serious injuries after the smash, which happened at 2.30am.

Wiltshire Police confirmed the The Independendent Office for Police Conduct has been called in 'due to police contact prior to the collision'.

A statement from the IOPC is expected.

It is thought a car went into the back of an HGV and lodged underneath. One person in the car had to be freed by fire crews using cutting equipment. Fire crews from Wiltshire were helped by colleagues from Gloucestershire and Berkshire to deal with the incident.

Police have appealed for witnesses to contact them on 101.