Investigators have yet to determine the cause of the suspicious 6am blaze which gutted two buildings at the former Kenmure Intermediate School site last week.
A police spokeswoman yesterday said the matter remained with investigators, but a cause had not been established.
Appliances from Dunedin, Lookout Point, Roslyn and St Kilda, as well as a command unit, responded to the fire which gutted two derelict buildings at the site in Kaikorai Valley Rd on Friday morning.
''The fire continues to be investigated and police are following strong lines of inquiry,'' the spokeswoman said.
Public Health South was notified following the blaze because of concerns of asbestos contamination.
Southern District Health Board medical officer of health Dr Derek Bell said he thought it was unlikely the buildings contained asbestos but samples were taken for analysis as a precaution.
That analysis had been delayed due to the Kaikoura earthquakes, he said.
''The site is not easily accessible to the public and not in a residential area,'' he said.
''The concern regarding asbestos is relevant to the clean-up/demolition, which will occur later on, once test results are known.''
Attempts to contact the site's owner have been unsuccessful.
