Police are investigating the death of 45-year-old Lee Matthews, of Orkney Court, Worthing, whose body was found at a house in Ivydore Avenue, Worthing, at 10.30am on Monday (July 9).
His death is being treated as unexplained and a post mortem took place on Tuesday (July 10).
This was inconclusive and police are awaiting toxicology tests.
A 47-year-old woman was arrested at the scene for the unlawful supply of a controlled substance. She has been bailed until August 9.
As part of the investigation, a quantity of prescribed medication was taken from the address.
The death was referred to the IPCC as there had been police contact with the two people the night before.The IPCC has considered the referral and it has decided that the matter should be subject of a local investigation.