Police are investigating a fire at a flat above a vacant shop in Sidley.
The blaze broke out on Sidley Street between 5.30pm and 6.30pm on Friday, September 20 and substantially damaged the property, according to Sussex Police.
A spokesman for the force said the fire may have been caused by an electrical fault.
East Sussex Fire and Rescue Service crews attended and eventually extinguished the fire by 11pm. No one was hurt.
A Sussex Police spokesman said the property had not been occupied for a year, but officers are keen to speak to anyone who may have information about previous occupants.
Detective Constable Lotte Scott said: “It would help us to know who had lived there or who may have used the premises in the meantime, possibly on a temporary basis.”
Anyone with such knowledge, or who has noticed any comings and goings over recent months, is asked to contact officers online or by phoning 101, quoting serial 1193 of 20/09.