FIRE investigators have just been given access to inside the Mackintosh Building four months after the blaze.

Residents are angry it has taken so long and fear that it could mean the cause of the blaze is not identified.

The fire service said following works to make the building safe they have now been given access to what remains of the building.

Demolition contractors have been taking down sections of the Mackintosh to be preserved for a future rebuild.

One fire expert said that delays have lead to deterioration but it can’t be known at this stage if that will hinder the investigation.

Dr Iain Sanderson, programme leader of Fire Risk Engineering at Glasgow Caledonian University,

said the investigation really starts as soon as crews drive up.

He said: “With everything that is exposed to the elements there is some degree of deterioration. As time progresses things will deteriorate, but there are ways of investigating.

“Normally you would get access quicker than they have but people wanted to preserve the building. “Because of the wish and desire to preserve the building it will have caused substantial delay.”

Residents groups and the community council have written to the Chief Fire Officer Alistair Hay asking about the investigation asking the delay in access and demolition work will “impact and likely cripple” the investigation”.

They asked: “What is the opinion of the SFRS regarding the apparent conflict of interest between the Art School having control of the building, whilst altering the structure itself through their contractors, potentially destroying valuable technical evidence pertaining to the origin and spread of the fire?”

David McGown, Assistant Chief Officer of the Scottish Fire and Rescue Service, said: “The investigation into the fire that took hold of the Glasgow School of Art, O2 ABC and surrounding buildings remains ongoing.

“Following work to ensure the safety of those working within the structure, our fire investigation experts have now been able to gain access to the inside of the Mackintosh building.

“Our specialist team continues to work alongside our police partners, and through a high volume of information from various sources.

“I would like to stress once again that this is a very complex process and will therefore take time.”

Pauline McNeill, Glasgow Labour MSP, said: “Residents are already anxious and they feel the lateness might compromise the investigation.”

A spokeswoman for the School of Art said : “We have been working to get to the stage where the building is safe to be accessed. We have been working from day one with the Scottish Fire and Rescue service on the investigation.”