The drugmaker, you may recall, is fighting allegations filed by Nigeria that it conducted an unauthorized trial on children at a government hospital in the state of Kano during a 1996 outbreak of measles, cholera and meningitis in which 12,000 people died. Of the 200 children given its Trovan antibiotic, 11 died and 189 suffered serious injury. Nigeria is seeking $7 billion from Pfizer, which argues it acted ethically and that the trial was authorized by the government.

As part of its defense, however, the drugmaker is suing to quash a 2001 government report that blamed Pfizer. Nigeria had established a panel headed by Abdusalami Nasidian, a ministry of health official, to investigate the trial and is relying on the report to press its case. Pfizer’s lawyers, however, are trying to discredit Nasidian by claiming he was biased, since he attempted to stop the Trovan trial when it took place seven years ago.

“We are in court to quash the Nasidi report which we say is unconstitutional,” Pfizer’s lawyer Anthony Ndigbe told reporters after the court hearing a federal high court hearing, according to Agence France-Presse. The report “is seriously in breach of fair hearing. Pfizer was never given the opportunity to cross-examine the witnesses that gave evidence before that panel. During the clinical trial itself, Nasidi personally came to the Infectious Diseases Hospital and tried to stop it. He was opposed to it, yet he was the same person appointed to chair the investigation and that report is the basis of the entire case of the federal government.”

But the government urged the court not to grant Pfizer’s request to reject the report, AFP writes. “Our position is that the report should not be quashed because the fact that he (Nasidi) raised objections to the clinical trial does not necessarily create any bias,” government lawyer Babatunde Irukera said. The presiding judge, Onwuri Chikere, adjourned the case to October 29 for a further hearing.

Separately, the Nigerian state of Kano is also suing Pfizer for about $2 billion and recently issued summonses for 10 Pfizer execs, including former ceo and current board member Bill Steere, to appear in court. If they don’t appear, they could be arrested by Interpol.