The drug Trovan was given to children in Kano state in 1996 in a study during a meningitis outbreak. Nigeria said it was used without approval and caused deaths and deformities. Pfizer said the trial was approved and settled the case in April 2009.
One of the cables revealed by WikiLeaks quotes Enrico Liggeri, Pfizer's manager in Nigeria, trying to forestall action at the federal level.
The cable, published by The Guardian in London, says: "According to Liggeri, Pfizer had hired investigators to uncover corruption links to Federal Attorney General Michael Aondoakaa to expose him and put pressure on him to drop the federal cases. He said Pfizer's investigators were passing this information to local media."
Articles later appeared in the Nigerian press accusing Aondoakaa of corruption. The cable continues: "Liggeri contended that Pfizer had much more damaging information on Aondoakaa and that Aondoakaa's cronies were pressuring him to drop the suit for fear of further negative articles."
Aondoakaa has not been convicted of corruption but a court declared him unfit to hold office.
Pfizer denied a campaign against him.