The revenue authority’s warehouse at the Jomo Kenyatta International Airport was burnt down on Monday.
Items destroyed by the fire included case files and exhibits for suits before court, as well as goods whose customs duty had not yet been paid.
The fire started at the office of Kenya Revenue Authority’s deputy commissioner Rose Gichira at around 5am before spreading to other areas.
However, by Monday evening, detectives had not reached Ms Gichira’s office since there is a huge crack on the wall that poses danger.
Firefighters from the Kenya Airports Authority and the military eventually put out the blaze at around noon.
They were initially overwhelmed when some of the goods started exploding.
Airport CID boss Joseph Ngisa said that no one was injured during the incident. The cause of the fire is yet to be established, he added.
It is feared that crucial evidence for matters before court could have been lost.
Last November, two police officers were arrested after they stole goods worth millions of shillings from the same godown. The case is pending before court.