The board, which oversees the functioning of all temples in Kerala's southern districts, said this in an affidavit to the court, putting an end to speculation on the so-called celestial light.
TDB said it had never called the phenomenon a divine light and for long the fire had been lit by tribals living on the hillock.
TDB's affidavit was filed in response to the demand made by the court that is currently looking into a series of petitions filed soon after the stampede at Sabarimala Jan 14 when the 'celestial light' had appeared three times.
Kerala Yukthivadi Sangham (KYS), a rationalist organisation, has been at the forefront of a campaign against what it calls cheating by the state government and the TDB.
Sanal Edamarukku, an office bearer of the KYS who has been fighting the practice of making an artificial light appear on the horizon and letting it pass as celestial, said finally their stand had been vindicated.
'This affidavit by the TDB has finally come and we are really happy that they spoke the truth,' said Edamarukku.
The Jan 14 stampede occurred when the pilgrims were returning after watching the 'celestial Makara Jyothi light', the most important event of a two-month pilgrimage dedicated to Lord Ayyappa, in Kerala's Pathanamthitta district.
According to believers, the sighting of the celestial light is auspicious and, over the last few years, there has been a huge influx of pilgrims from the three southern states to witness it.
The number of pilgrims visiting the shrine has been going up every year.