Nigeria's drug regulator has recalled a batch of Johnson & Johnson children's cough syrup after tests showed it contained "an unacceptable high level" of a toxic and potentially fatal substance.

The substance, Diethylene glycol, "was found to cause acute oral toxicity in laboratory animals", Nigeria's National Agency for Food and Drugs Administration and Control (Nafdac) said on Wednesday.

It added that human consumption of the Diethylene glycol results in toxic effects, including abdominal pain, vomiting, diarrhoea, inability to pass urine, headache, altered mental state, and acute kidney injury which may lead to death.

The substance has been linked to the recent deaths of dozens of children in Cameroon and The Gambia.

Laboratory tests on the recalled Benylin Paediatric syrup also showed that it caused "acute oral toxicity in laboratory animals", the regulator added.

Neither Johnson & Johnson nor Kenvue - which owns the Benylin brand after becoming independent from Johnson & Johnson last year- have commented on the Nafdac's statement.

The syrup was manufactured in South Africa in May 2021 and had an expiry date of April 2024.

The syrup's packaging says it can be used for relieving cough and congestive symptoms and for treating fever and other allergic conditions among children aged between two and 12 years.