Nigeria says it has discovered new material it believes will strengthen its $7 billion lawsuit agains the U.S. drugmaker Pfizer and has withdrawn the case in preparation for filing a new lawsuit. For VOA, Gilbert da Costa reports from Abuja.

The Nigerian government has accused Pfizer of taking advantage of a 1996 meningitis epidemic to test an experimental drug without the authorization or full understanding of the families involved in the trials - allegedly contributing to the deaths of some of the children and sickening others. Pfizer denies wrongdoing.

The lead lawyer for the Nigerian government, Babatunde Irukera, told VOA that lawyers recently discovered material that suggested Pfizer committed fraud.

"It was a legal strategy to expand what we believe our claims are." said Irukera. "We sought to amend the statement of claim before the court and the request was denied. And we believe the material we wanted to put before the court is vital to a fair and judicious adjudication of the case."

The government says now that the case has been withdrawan, it will be refiled with the new evidence.

Proceedings have so far being bogged down by legal technicalities. Pfizer's lead counsel, Afe Babalola, argues the government has not been very convincing in defending its case.

"This is not the first time they [government] is running into problems," said Babalola. "As it is now, the case is out of court. My client [Pfizer] will be happy that every step taken so far has been successful for them."

But Irukera says the evidence against Pfizer is overwhelming.

"We believe that the case the federal government has against Pfizer is a good case," he said. "There is overwhelming evidence that Pfizer perpetrated all kinds of fraudulent activities and also engaged in these trials illegally."

"There are victims who are living today, there are some families of the victims who have died, what they understood at the time Pfizer came to Nigeria was that Pfizer was volunteering treatment. They did not think they were volunteering their children as guinea pigs for clinical examination," he continuted.

Pfizer has sought to have the case thrown out on the grounds that Nigerian law required that the lawsuit to be filed within six years of the incident. Pfizer also insists it obtained authorization for the drug trials.