A 38-year-old man has died in police custody in Reading.
Officers responded to an incident in the town at around 2.15am on Wednesday and arrested the man on suspicion of assault.
He was taken to Loddon Valley police station.
During his detention he was found unresponsive at around 7.10am on Wednesday.
Officers and ambulance staff gave emergency life support to him but sadly he was pronounced dead at the Royal Berkshire Hospital.
His next of kin have been told.
Thames Valley Police has made a referral to the Independent Office for Police Conduct (IOPC) following the man's death.
The IOPC has decided to independently investigate the death.
Thames Valley Police says it is fully co-operating with the investigation and will continue to do so.