The 20-year-old, who cannot be named because he was juvenile at the time of the offence in 2012, told people he burnt down Oxley High School in the wake of the fire, but only yesterday admitted responsibility in Tamworth Children’s Court.

But it was the rubber gloves the then 17-year-old used to break into the school about 3.30am on March 18 and that were left just metres away from the scene that gave police the forensic breakthrough they needed to arrest and extradite the man from Victoria in May.

The suspicious blaze quickly spiralled out of control and destroyed the Castlereagh classroom block, which housed physical education rooms, science labs and English classrooms, and left a damage bill of more than $10 million.

Investigators sifted through the charred remains for clues as to who was behind the blaze, before arson samples and the latex gloves were forwarded for specialist forensic analysis.

The gloves were swabbed for DNA and the man’s profile was identified, linking him to them.

According to court documents tendered yesterday, the man told a number of people he broke into the PE staff room with a chair and ransacked the rooms.

“It is alleged that, during these conversations, he made a number of admissions to being with the accused and breaking into the school and lighting the fire,” facts tendered to the court said.

“[He] then lit the fire to wipe out any evidence and smashed a further window to get out of the building.”

On March 24, the same witnesses were cleaning the man’s home when they located several items with the words “Oxley HS” engraved on them before police were called.

The man left Tamworth for Sydney soon after the fire and, after the forensic hit earlier this year, was extradited and refused bail, where he has remained.

Solicitor Fiona Hadlington said the man, who appeared in court via videolink yesterday, admitted to a charge of aggravated break-and-enter and commit serious indictable offence, after breaking into the school and stealing a video camera, digital camera, a clarinet, starter pistol, compact discs and an amount of money.

He admitted to intentionally or recklessly destroying the Castlereagh block of the school by fire whilst in company, and also pleaded guilty to two counts of failing to appear, after he skipped court in April 2012 and September 2013 while on bail.

A second charge of aggravated break-and-enter and commit serious indictable offence, as well as a goods in custody offence, were withdrawn and dismissed in court yesterday.

Magistrate Michael Holmes ordered authorities to compile a background report before the man is sentenced in September.

The man remains bail refused.

In March, Christopher King-Cougan was arrested and charged in connection to the suspicious blaze.

The former student appeared in Tamworth Local Court last week, but the case was adjourned, because of an outstanding fire statement.

He remains on bail to reappear in court later this month.