A man has been freed on bail after being arrested on suspicion of murdering a woman whose body was found by a colleague due to take her to work.
Police were called to Cherry Tree Cottage in East Ashling, near Chichester, at 8am on Monday after Debbie Levey, 44, was discovered dead in the house.
A 45-year-old man from Selsey, who was known to Ms Levey, was arrested on suspicion of her murder and released on conditional bail until February 21, pending further investigation.
Sussex Police said that a post-mortem examination failed to find a cause of death, and further tests will be conducted.
While initially it was thought that we were dealing with a sudden death, officers became increasingly suspicious of the circumstances.
"At this stage our inquiries lead us to believe that this may not have been a natural death and a murder inquiry was launched on Monday."
Officers appealed for information from anyone who saw or was in contact with Ms Levey between Sunday at 12.30pm and Monday.
People were also sked to come forward if they saw a blue Vauxhall Vectra parked in a lay-by across the road from Cherry Tree Cottage on Sunday afternoon or early that evening.