Nigeria's National Agency for Food and Drug Administration and Control (NAFDAC) announced the recall after laboratory tests found an unacceptably high level of diethylene glycol, prompting regulators in five other African countries to recall the syrup.

Consuming diethylene glycol can result in acute kidney injury. The substance has been linked to the deaths of dozens of children in Gambia, Uzbekistan and Cameroon since 2022 in one of the world's worst waves of poisoning from oral medication.

Fraden Bitrus, NAFDAC's director of pharmacovigilance, told Reuters the regulator had been testing cough syrups in response to those deaths, not because of any specific report of harm to children in Nigeria.

"We sampled a number of products. Some failed and some passed. This particular product had been sampled earlier but we were not thinking of diethylene glycol and because of this, we decided to test the product again," he said.

The recalled batch of Benylin Paediatric syrup was made by J&J in South Africa in May 2021, although Kenvue now owns the brand after a spin-off from J&J last year.

Asked whether J&J was working with Kenvue to investigate what had gone wrong, Joe Wolk, chief financial officer of J&J, told Reuters: "This is just with Kenvue at this point."

Kenvue has said it was conducting its own assessment and working with health authorities to determine next steps.

After Nigeria's announcement last week, Kenya, South Africa, Tanzania, Rwanda and Zimbabwe all recalled the same batch of syrup, while South Africa also recalled an additional batch.

(Additional reporting by Patrick Wingrove in New York; Writing by Chijioke Ohuocha and Estelle Shirbon; Editing by Alexander Winning and David Evans)

By Ope Adetayo