Police in Christchurch have renewed their appeal for information over two arsons earlier this month.
One destroyed the century-old Billens Building in High Street, which was considered an important part of Christchurch's heritage.
The other hit a building in Moorhouse Avenue.
Both happened on 7 December between 9.20pm and 10.10pm.
Police said both fires appear to have been deliberately lit.
They have completed their examination of the Moorhouse Avenue site but have been hampered at the Billens Building by earthquake damage that made the site dangerous to enter.
Police said they would like to hear from people in the area at the time who might have photographed the fires on mobile phones.