South Africa looks into Nigerian death in custody
South African state pathologists are to carry out a post-mortem on a Nigerian man who died after being arrested near Johannesburg on Saturday.
A protest immediately followed, with 300 people surrounding the vehicle where he died, local media report.
The allegation that he was suffocated is being investigated by an independent police complaints body.
Police say that he died after swallowing drugs as they were about to arrest him for possession.
Independent Police Investigative Directorate spokesperson Robbie Raburabu told the News24 website that "as soon as he saw the police coming he swallowed the drugs and overdosed and died on the scene".
But Mr Raburabu told the BBC that all the circumstances surrounding the man's death, including the possibility of suffocation, is being looked into by pathologists.
Police used rubber bullets to disperse the crowd of about 300 protesters in the Kempton Park area on Saturday, Eyewitness News reports.
The Nigeria Union in South Africa say that this is not the only incident of a Nigerian being mistreated while being held by South African police.
"We take exception to the continued torture of Nigerians by the South African police," said the union's president, Ikechukwu Anyene, Nigeria's Premium Times newspaper reports.
There have also been demands for the Nigerian community to commission its own post-mortem.