Police are continuing to question a man in connection with the death of a 35-year-old woman in Warwickshire.
Police were called to a house on Coleshill Road in Atherstone at 2215 BST on Sunday to investigate reports of an overdose.
A 32-year-old man was arrested in connection with the incident on the same night.
Warwickshire Police said they would be applying to the magistrates court on Tuesday for an extension to the time they can keep the man in custody for questioning.
A police spokeswoman said a post mortem examination carried out on Monday proved inconclusive and they were awaiting the results of further tests.
"Formal identification of the woman is due to take place later this morning and her identity cannot be released until then," the spokeswoman said.