There was extensive fire damage to the top floor of the building with more moderate water and smoke damage to ground floor units.
"We now believe that his was a malicious, deliberate and pre-planned arson. The occupier of the unit where the blaze started is assisting police with our inquiries but we need the public's assistance to help identify the person shown,'' Detective Senior Sergeant Grant Ferguson said.
"The scene examination has revealed that an explosion has occurred but we are awaiting forensic results to determine if the explosion caused the fire or the other way around.
"The fire has affected a large number of people who have lost many items valuable to them and we encourage them to contact us using the email address,'' he said.