The man was driving Joshua and two of his friends, Latif Ayodele and Sina Ghami, on a busy highway linking Lagos and Ibadan in southwest Nigeria when the Lexus SUV in which they were travelling rammed into a stationary truck on Monday.
Nigerian police and state officials said that Ayodele and Ghami died at the scene, while Joshua and the driver sustained minor injuries.
"The driver is currently in custody in connection with the Anthony Joshua accident," Oluseyi Babaseyi, spokesman for the police in Ogun state, told AFP. "Investigations are ongoing."
When asked if the driver was facing prosecution, Babaseyi replied that the "investigation remains discreet for now".
Preliminary investigations showed that the vehicle was moving at an excessive speed and had burst a tyre before the crash, the Traffic Compliance and Enforcement Agency (TRACE) in Ogun state, where the accident occurred, told AFP earlier in the week.
After leaving the hospital on Wednesday, Joshua and his mother paid their respects at the funeral home where the bodies of his friends were being prepared for repatriation.
A government source suggested to AFP on Thursday that the remains of the victims may have been repatriated to the United Kingdom.
