WikiLeaks: Pfizer denies dirty tricks claims in Nigeria

US pharmaceutical giant Pfizer has dismissed as "preposterous" reports that it hired investigators to uncover evidence of corruption against a former Nigerian attorney general.

According to a US cable released by WikiLeaks, Pfizer wanted to "put pressure" on Michael Aondoakaa.

He was heading a lawsuit against the company over a 1996 drug trial during a meningitis epidemic.