The National Air Cargo flight plunged into the ground and exploded shortly after take-off at the US-run Bagram airbase north of Kabul on April 29, killing all seven crew members.
"One possibility, though it's not confirmed, is that it was the displacement of the load in the back of the plane," Nangyalai Qalatwal, the Afghan transport ministry spokesman, told AFP.
"The plane took off and, if confirmed, the load displaced and hit the back of the plane, further lifting the nose and causing the crash."
National Air Cargo issued a statement after the crash saying all cargo in the aircraft, a Boeing 747, was properly loaded and secured, and had passed the regular safety inspections.
The flight was heading to Dubai from Camp Bastion in Helmand province after re-fuelling at Bagram.