Thames Valley Police is appealing for witnesses to a suspicious fire in Wokingham.
The fire happened at the Grade II Elms building in Broad Street at just before 3am on Wednesday 7 September.
Around 50 firefighters from eight fire stations were called to the property, which is 600 square metres over two floors and includes a basement. The fire was under control just after 7.30am but the incident was not closed until just before 2.30pm.
The fire started in the basement and gutted the inside, damaging a substantial amount of the property, including its roof. Firefighters had to remove a chimney on the roof in order to enter the building and make it structurally safe.
The building was not in use but was being converted into flats.
Detective sergeant Carl Bradford, from Loddon Valley CID, said: “At this stage it is too early to say that this was definitely arson as we are not currently settled on what caused the fire.
“However, we are investigating it as a suspicious fire and would like to trace any witnesses.”
Police have arrested and bailed a man as part of its investigation. He is due to report back on 5 October.
