The probe committee has not found evidence of sabotage in December 26 fire at Secretariat's Building No. 7.
According to the investigation committee, led by Home Ministry Senior Secretary Dr Nasimul Gani, a loose electrical connection caused the fire.
The probe committee submitted its initial investigation report to Chief Adviser Dr Muhammad Yunus at State Guest House Jamuna on Tuesday.
At a press briefing held at State Guest House Jamuna the Chief Adviser's residence, Dr Gani said during primary investigation, the committee found no evidence of sabotage.
Committee member Maksud Helaly, also a professor of Bangladesh University of Engineering and Technology, told media that the committee submitted its preliminary report to the Chief Adviser.
He said that during an hour-long meeting with the committee members, the Chief Adviser learned about the fire.
The probe committee with other investigating agencies will prepare the final report soon, he said.
The fire broke out at Secretariat's Building No. 7 at 1:52am on December 26, severely damaging floors fifth to eighth.
It took 19 firefighting units 10 hours to douse the fire.
The Road Transport and Highways Division on the eighth floor, the Posts and Telecommunications Division and the Local Government Division on the seventh floor, suffered significant damage, according to officials.
