Fifteen years ago, the pharma giant Pfizer used an experimental drug Trovan to combat a meningitis outbreak in Northern Nigeria, allegedly without obtaining informed consent from participants and government officials. The Nigerian government sued Pfizer, but company officials purportedly complained of being unfairly targeted, stating that the humanitarian organization Médecins Sans Frontières (MSF) also used the same antibiotic to stave off the epidemic. Now, MSF, in a press release issued this week, has denied claims that their physicians administered the antimicrobial during the 1996 meningitis outbreak.

“We did not use Trovan in Nigeria,” Marc Gastellu, former MSF operations manager for Nigeria, told Nature Medicine. “There was no cooperation between Pfizer and our teams.”

The claims, reportedly made by Pfizer’s managing director for the country during a meeting with US Embassy officials in the Nigerian capital Abuja, surfaced last month during the disclosure of a flood of diplomatic documents released by Wikileaks. The antibiotic, at the time being field-tested by the New York-based drug maker, was not approved to treat meningitis.

In an about-face, Pfizer is now challenging the assertions of its Nigerian official, and supporting MSF’s position. “The allegations contained in news reports surrounding this US Embassy cable are false, including the notion that MSF administered Trovan during the 1996 meningitis outbreak,” Pfizer wrote in a statement. “To our knowledge, that did not happen. We regret any confusion that these news reports may have generated.”

Pfizer, however, still stands by their efforts during the outbreak. In 2009, Pfizer settled the lawsuit, but stopped short of claiming responsibility for the five children that died during the Trovan trial. The company argued that their deaths instead arose from complications linked to the disease.

Image of meningitis bacteria from the CDC