The US pharmaceutical giant Pfizer has been slapped with criminal charges in Nigeria over a notorious clinical trial it conducted on children during a meningitis epidemic a decade ago. Patients became unwitting guinea pigs for a new, untested antibiotic and many of them either died or were left with permanent disabilities.

Pfizer and its representatives will be called to account at hearings due to begin next month in the Nigerian state of Kano, where public anger over the clinical trial - and the assurances of any pharmaceutical company - remains so high that the local population won't even trust the Nigerian government to immunise their children against polio.

The episode, which has already led to one unsuccessful suit in the US courts, was the inspiration for John Le Carre's novel The Constant Gardener and is frequently held up as an instance of scientific inquiry gone shockingly awry.

The Nigerian authorities say Pfizer researchers selected 200 children and infants from a crowded epidemic camp in Kano in 1996 and gave about half of them an untested antibiotic called Trovan. The lawsuit alleges that the researchers did not obtain consent from the children's families even though they knew from their own research that Trovan might have life-threatening side effects and was "unfit for human use".

The suit further contends that the researchers gave the other half a comparison drug made by Pfizer's competitor Hoffman-La Roche, but deliberately underdosed them to make their own product look better. Pfizer and its doctors "agreed to do an illegal act," the suit says, "in a manner so rash and negligent as to endanger human life".

Once the trial was over, the suit continues, Pfizer left the area, removed all medical records and "obliterated any evidence" of the trial. A Nigerian government report, which appears to have spurred the criminal charges, previously found that Pfizer never told the children or their parents they were participating in a trial and did not inform them that alternative treatments were available - most obviously chloramphenicol, a relatively cheap antibiotic usually recommended for bacterial meningitis.

The government report found that of the 11 children who died, five were taking Trovan and six were taking low doses of the comparison drug, ceftriaxone. An unknown number suffered deafness, blindness, paralysis and other disabilities.

The Kano authorities have charged Pfizer on eight counts of criminal conspiracy and voluntarily causing grievous harm. They have also filed a civil suit seeking more than $2.7bn (£1.3bn) in damages. Pfizer has responded to the lawsuit by insisting it did nothing wrong. "Pfizer continues to emphasize - in the strongest terms - that the 1996 Trovan clinical study was conducted with the full knowledge of the Nigerian government and in a responsible and ethical way consistent with the company's abiding commitment to patient safety," a company statement said. "Any allegations in these lawsuits to the contrary are simply untrue - they weren't valid when they were first raised years ago and they're not valid today."

Back in 1997, when Pfizer faced a US government audit of its records on Trovan, the company produced a letter from a hospital in Kano saying its study had been approved by the hospital's ethics committee. The company's accusers contend that the letter was fabricated after the fact, using a forged letterhead. The hospital, according to the suit, has no ethics committee.

Nigeria's decision to prosecute Pfizer marks the first known instance of a Third World country going after a pharmaceutical multinational. Until now, the Nigerians have trod very carefully around the issue - commissioning an investigation but then suppressing the results until they were leaked to The Washington Post a few years ago.

But the episode has got in the way of successive public initiatives, including a polio vaccination drive that prompted an 11-month boycott in Kano.

Trovan has never been approved for use on US children. It was cleared for adults in 1997, but its use was restricted two years later following reports of liver damage and death. It is banned throughout Europe.