After a dominant start in the match, Onuachu opened the scoring for Nigeria in the 28th minute.
The late Ghami was among the team members who managed Joshua to his historic heavyweight titles over Wladimir Klitschko in 2017.
Morocco finished the group stage as Group A winners with seven points.
Oswin Appollis sealed the victory for South Africa eight minutes from normal time.
The government officials explained that a vehicle conveying a team of four, collided with a stationary truck.
In total, Joshua has a record of 28 wins, four losses, and zero draws in 32 professional career fights.
Chelle said this ahead of the West African nation’s last Group C match against Uganda in the ongoing Africa Cup of Nations on Tuesday.
Photos of Joshua in a wrecked vehicle at the accident scene emerged on social media amid rescue efforts.
Algeria will now face already-eliminated Equatorial Guinea in its final group match, while Burkina Faso will battle Sudan in a high-stakes clash.
The victory moved Mozambique to third in Group F and a draw in their last game against Cameroon could be enough to reach the round of 16.
