Police have confirmed a woman has died and a man is in a serious condition in hospital following a crash involving three vehicles on the M4 between Reading and Newbury.
Officers were called to the eastbound carriageway between Junction 13 for Newbury and Junction 12 for Reading at around 1.55pm on Friday 17th July.
Three vehicles, a white Astra van, a black Landrover Freelander, and a white Audi A3, were involved.
The driver of the Landrover, a 73 year-old woman from Wales, died at the scene of the crash.
The passenger in the same vehicle, a 74 year-old man, also from Wales, was airlifted to hospital with serious injuries.
Police say no one else was injured.
A 40 year-old man from West Sussex has been arrested on suspicion of causing death by careless driving and remains in police custody.
Investigating Officer, Sergeant Darren Brown of the Roads Policing Unit, said: "Our thoughts at this time remain with the family of those affected by this collision.
"An investigation has started and we would like to hear from anyone who has information which could help.
"If you saw this collision happen or think you have dash-cam footage that may have captured this incident, please get in touch.
"You can contact Thames Valley Police by calling the non-emergency number 101, or by making a report online, please use the reference number 43200219124."