Scrutiny of a trial carried out by Pfizer in Nigeria in – allegedly in breach of international law – has been reopened after the conclusions of a government advisory panel were obtained and published by the Washington Post.

Pfizer has been accused of testing an unapproved drug on children in at the Kano Infectious Diseases Hospital in Nigeria in 1996, without the go-ahead of the country’s government, and legal action against the firm by the families of some children involved in the study was initiated in 2001.

Last November, a US federal judge dismissed a lawsuit that accused the drugmaker of not properly warning patients about the risks of the drug - which was withdrawn from sale in 1999 after being linked to liver damage - and said the case should be heard in a Nigerian court.

The unearthed panel report – carried out some five years ago but never published – concludes that the study was an ‘illegal trial of an unregistered drug’, and a ‘clear case of exploitation of the ignorant’, according to the Post.

In the study Pfizer administered an oral formulation of its quinolone antibiotic Trovan (trovafloxacin) to nearly 100 children with meningitis during an outbreak of a particularly virulent form of the disease which ultimately killed 15,000 people. Five children died after being treated with the experimental antibiotic, although there was no direct evidence the drug caused their deaths. Six children died while taking a comparison drug.

Pfizer contended that the treatment was delivered for philanthropic reasons, and followed all necessary informed consent guidelines in selecting patients, but this assertion was rejected by the panel, according to the Post.

The US drugmaker said in a statement that the Nigerian government has “neither contacted Pfizer about any of the committee’s findings nor are we aware that the committee has approved a final report.”

Hundreds died in the epidemic for lack of any available treatment, but the fatality rates in the Trovan and comparator ceftriaxone groups were lower than published results for other forms of treatment, said the firm.

“Trovan unquestionably saved lives, and Pfizer strongly disagrees with any suggestion that the company conducted its study in an unethical manner,” it added.

On the issue of informed consent, Pfizer said: “The experimental nature of the Trovan treatment was explained to the parent or guardian of every participating child, in two different languages -English and the local language, Hausa - by local bilingual nurses. Verbal consent was obtained in all cases.”