Directorate of Criminal Investigations (DCI) detectives investigating the cause of Malik Heights fire said on Wednesday that the incident was an act of arson.
The detectives revealed that the reviewed CCTV footage shows a suspected arsonist identified as Abdirizak Yusuf Adow entering the building with a jerican believed to contain fuel.
The footage also shows the suspect sprinkling fuel at the parking lot and igniting a fire before taking off using the staircase.
Police said they have launched a manhunt for Adow and have visited his Eastleigh and Kileleshwa homes but he was not found. Adow, a former broker at the business, is believed to be bitter.
Alhusnain Motors Limited reported they lost 69 high-end vehicles worth hundreds of million shillings in the incident.
The nine-storey building that houses motor vehicle bazaars, offices and restaurants went up in flames on Monday night at around 8pm.
Explosions could be heard from inside the building as efforts to put out the fire and salvage vehicles parked in the basement were underway.
The building was officially opened for business in 2017.