The plane came down despite no apparent mechanical problems during an internal flight in the Democratic Republic of Congo.
It has now emerged that the crash was caused by the concealed reptile escaping and causing a stampede in the cabin, throwing the aircraft off-balance.
A lone survivor apparently relayed the bizarre tale to investigators.
The crocodile survived the crash, only to be dispatched with a blow from a machete.
One of the passengers had hidden the animal, which he planned to sell, in a big sports bag, from which the reptile escaped as the plane began its descent into Bandundu.
A report of the incident said: "The terrified air hostess hurried towards the cockpit, followed by the passengers."
The plane was then sent off-balance "despite the desperate efforts of the pilot", said the report.