He was immediately rushed to the hospital after the incident. Two other people died in the accident.
Joshua was known to be in an SUV that collided with a stopped truck.
Unverified footage on social media shows Joshua in pain as he is helped out of the damaged vehicle.
The Ogun State Police said Joshua sustained minor injuries when the car he was in collided with a truck.
The former British world heavyweight champion was seen sitting in the back seat of the vehicle, before being pulled from the wreckage by a crowd of onlookers.
In the footage, Joshua appears conscious but grimaces in pain.
Another short video shows Joshua in an ambulance, wearing only shorts.
Police confirmed that Joshua was taken to hospital and the cause of the accident is still under investigation. Two people were pronounced dead at the scene.
