Nigerian families can sue the Pfizer drugs giant in the US over its alleged role in the deaths of children, a US appeals court has ruled.
The decision overturns a ruling by a lower court that the case must be heard in Nigeria.
Pfizer is accused of killing 11 children and injuring 181 others when an antibiotic was tested on them during a meningitis epidemic in 1996.
Pfizer denies the claims, saying they were victims of the outbreak.
The epidemic killed 12,000 children in Nigeria in six months.
The families say that Pfizer tested out an oral antibiotic called Trovan on some 200 ill children in hospital in Kano, without first getting the consent of their parents.
They say the drug killed 11 children and caused blindness, deformities and brain damage in others.
Their original law suit had been dismissed on the grounds that it could not be pursued under the Alien Tort Statute, an old law allowing foreigners to sue in the US courts.
But the Second Circuit US Court of Appeals in New York ruled that the statute could be used.
Peter Safirstein, a lawyer for the Nigerians, said the ruling was "very, very important".
Pfizer has always maintained that the tests were carried out with the approval of the Nigerian government and that the children's parents were fully informed.
In a statement, the company said it had great sympathy for those affected by the epidemic but that "all clinical evidence points to the fact that any deaths or injuries were the direct result of the illness, and not the treatment provided to patients in the Pfizer study".
Pfizer said it remained "confident that it will prevail".