Mohd Nadzniezan Shah Mohd Nadzir, was killed when the four-wheel drive vehicle crashed into a ravine in Jalan Kg Umpason Apin-Apin, Keningau at about 10.50am.
Keningau District Police Chief DSP Robert Salisip David said, the family was travelling from Keningau heading to Sandakan to sell vegetables.
"In the incident, an Isuzu D-Max four-wheel drive was driven by the victim's father Mohd Nadzir Abu Bakar, 35, from Kinabatangan. Also in the car were the victim's mother Seriani Masri, 39, and his aunt, Norsuhadam Abu Bakar, 34, and his uncle, Mohd Hafiz Abdullah Ulis, 24.
"On arrival at the location, the driver lost control of the vehicle which was laden with vegetables and crashed into a deep ravine about 20 meters off the road," he said.
Robert said all the victims were rushed to the Keningau Hospital by other road users passing through the area, except Norsuhadam Abu Bakar, who suffered injuries to her back and could not move. She was later brought out by the Fire Department.
"We received information from doctors in Hospital Keningau later that Mohd Nadzniezan Shah had died at the hospital due to injuries to his neck," he said.