In its statement, Nigeria’s foreign ministry said Iroegbu was reportedly killed in Pretoria by officers from the Tshwane Metro police department.

Joe, killed on 28 June, was attacked outside his shop in the city of eMalahleni, the ministry said.

Abuja said it was placing the South African government “on notice” and that “all options remain on the table… if the uncultured and provocative trend of intolerance and apartheid-style behaviour of South Africa against foreigners is not addressed”.

Nigeria has said it will seek compensation from South Africa for its citizens who have left the country, adding that Abuja had begun documenting businesses and properties left behind by Nigerians.

However, at a media briefing on Friday, South African cabinet minister Khumbudzo Ntshavheni said her government would not pay compensation and that Nigerians can sell registered properties they left behind on the South African market.

She also said: “We would be interested to know where the drug dens of Nigerians are, so they can show us where they have been holding the drugs so we can clean the drugs in South Africa quite urgently.”

Nigeria’s foreign ministry strongly condemned this comment in their statement on Sunday, calling it “unacceptable”.

“Such derogatory, unprofessional and uncensored generalised public statements by highly placed government officials constitute hate speech,” the ministry said.