The precarious state of the Victoria Road School structure has made it impossible for a joint police and fire investigation to begin.
The building was badly damaged in the blaze that took hold in Aberdeen on Friday May 10, with more than 40 firefighters battling the flames at its height.
Police said yesterday the school was still not safe to enter and so a full investigation into the cause of the fire has yet to be carried out.
In the meantime, Detective Inspector Allen Shaw appealed for witnesses who saw “anything unusual or suspicious” ahead of last week’s fire to come forward.
He said: “It has not been possible to carry out a joint fire and police investigation at this stage.
“We are carrying out inquiries to establish the full set of circumstances and would appeal for anyone with information or who saw anything unusual or suspicious around the time of the fire to call us on 101.
“We are continuing to work closely with our partners, including the fire service.
“There is nothing to suggest any suspicious circumstances but we are keeping an open mind.”
Police seek witnesses to Victoria Road School fire