The government-formed probe committee on Saturday began its investigation into the Friday's fire incident at Bashundhara City Complex.
After visiting the spot, the committee members said they would keep in mind all possible causes including sabotage behind the fire incident.
The probe body will examine whether the complex was equipped with modern and automated fire-fighting equipment and if so, why those did not work.
Meanwhile, Prime Minister Sheikh Hasina visited the mall on Saturday where a fire broke out on the 17th floor at killing seven people and injuring 20 others.