The man, from Hastings, was questioned after the 55-year-old woman was found dead on Wednesday 13 November.
He has now been released on bail until 19th December while officers carry out further inquiries.
The woman has not yet been formally identified.
– Det Chief Insp Jon Fanner, Sussex Police
"We are treating the death as unexplained at this time and are keeping an open mind as to what has happened.
"I am still keen to speak to anyone who was in the area and may have seen the woman from 7pm to 10.35pm on Wednesday, or who saw or heard anything suspicious, to contact us.
"Please call us if you know anything, no matter how insignificant you might think it is. It could be important to the investigation."
Anyone with information should call 101 quoting Operation Bakewell, email firstname.lastname@example.org or call the independent charity Crimestoppers anonymously on 0800 555111.