Experts have been unable to identify the cause of the inferno which destroyed a school's swimming pool complex in January.

Enormous flames engulfed the wooden building housing the swimming pool at the City of London Freemen's School, in Ashtead Park, on the night of Friday, January 4.

After the fire, a spokeswoman from Surrey Fire and Rescue suggested it may have been an arson attack and police sniffer dogs were brought in to check for accelerants.

But speaking on Monday, almost three months later, the school's headmaster said the blaze was so intense that it consumed the evidence which would have allowed fire investigation experts to pinpoint the cause.

Philip MacDonald said: "Following investigation by the fire services, police and insurers, there is no clear indication of the cause of the above fire, as the intense heat from the fire left very little evidence for examination to reach a clear conclusion."

Mr MacDonald said the school plans to replace the swimming pool and a decision will be made following surveys of the remains.

Even before the fire, the school’s development master plan provided for the replacement of the swimming pool in the long term.

He said: "CLFS students have swimming sessions currently in two other local schools. This school is very grateful to Downsend School and Epsom College who have been very helpful in providing facilities for swimming following the fire."

On the night of the fire, dozens of local residents turned out in heavy rain to watch the huge flames leaping into the air.

Fortunately the efforts of the fire brigade and the building's location prevented the fire spreading to other buildings.

A Freemen’s pupil, who saw the remains immediately afterwards, said, "there was nothing left but black ash and the girls showers!"

Just a month later, on February 10, the fire brigade was again called to the school, this time to put out a blaze in the roof of the Old Boys Club House.