The post mortem examination into the death of a 17-year-old girl from Bedfordshire has proved inconclusive.
Esme Blore died at Northamptonshire General Hospital after attending the Reading Festival last weekend.
Further tests and toxicology reports will now take place.
Police today confirmed a second girl was also treated at hospital but has been discharged.
Northamptonshire and Thames Valley Police, along with the Royal Berkshire Hospital and Northampton General Hospital, are continuing to investigate the circumstances surrounding the teenager's death.