British former world heavyweight boxing champion Anthony Joshua has been involved in a car accident in Nigeria's Ogun State in which two of his close friends were killed, his promoter Matchroom Boxing has said.

Joshua, 36, sustained minor injuries when his vehicle collided with a truck on Monday, local time, according to Ogun State Police Command.

It added that the boxer had been taken to hospital and that police were investigating the cause of the accident.

Anthony Joshua is in hospital in a stable condition, but two of his friends — Sina Ghami and Latif Ayodele — were killed. (Supplied: BBC)

Nigeria's Federal Road Safety Corps (FRSC) said five men were involved in the accident on the Lagos-Ibadan Expressway.

Joshua suffered minor injuries; however, two people died, and two walked away unhurt, the FRSC said.

Officials have not said who was driving the car carrying Joshua, who was helped out from the back passenger seat. Investigations are ongoing.

"With profound sadness it has been confirmed that two close friends and team members Sina Ghami and Latif Ayodele have tragically passed away," Matchroom Boxing said in a statement.

It confirmed that Joshua had been taken to hospital for checks and treatment, and although stable, he would remain under observation.

Footage from the scene shows Joshua — clad only in shorts and shoes — wincing as he was led away from the wrecked car.

Footage from the scene shows Anthony Joshua wincing as he is led away from the wrecked car. (Supplied: BBC)

The Ogun state government said that Joshua and another passenger were evacuated to a specialised medical facility in Lagos, where doctors confirmed both did not require emergency intervention.

Joshua has since spoken with his family, the statement posted on X added.

Nigerian President Bola Tinubu expressed sympathy to Joshua and the families of the victims, calling the incident a "tragic accident".

The FRSC said preliminary findings suggest the vehicle carrying Joshua was likely speeding when it lost control during an overtaking manoeuvre and crashed into a stationary truck parked by the roadside.

"The primary causes of the crash being excessive speed and wrongful overtaking constitute serious traffic violations and remain among the leading causes of fatal road crashes on Nigerian highways," the FRSC said on X.