Police were called to the address in Marine Parade about 10.40am on Saturday 17 December.
Despite the best efforts of paramedics who commenced CPR, a local woman in her 20s was sadly pronounced deceased at the scene.
A post-mortem revealed she tragically died of a medical condition.
A 42-year-old man from Worthing was arrested on suspicion of murder pending the results of the post mortem; he has since been released from custody and will face no further action.
Detective Superintendent Alex Geldart said: “This is a tragic case and our thoughts are with the young woman’s family and friends at this difficult time.
“I’d like to extend my thanks to the public for their patience and understanding while we responded to the scene, and to the police responders, paramedics and the Helicopter Emergency Medical Service for their efforts.
“This will now be a coronial matter.”
