Nigeria has filed a $7 billion lawsuit against pharmaceutical giant Pfizer over clinical trials conducted on meningitis patients a decade ago that led to various side effects or even death.

The law suit claims Pfizer “illegally and pretentiously” conducted the tests 11 years ago, on children affected by the meningitis epidemic from April 10096, in Kano. Nigerian medical authorities allegedly did not approve the tests with Trovan.

Officials said Tuesday that children treated at the time with the Pfizer product suffered varying degrees of adverse effects like deafness, muteness, paralysis, brain damage, loss of sight, slurred speech and death.

Counsel to Pfizer, Afe Babalola, denied all the allegations against his client. Babalola added that Trovan had been used in the U.S. and Europe on more than 50,000 people. He stated none of theme had suffered adverse side effects or died.

The case is set to be heard in the Federal High Court in the capital Abuja on June 26.

Pfizer, one of the world’s largest pharmaceutical companies, released a statement in May claiming the Trovan tests “indisputably helped save the lives of almost 200 children stricken with meningitis.”

Nigeria is claiming $500 million in the lawsuit from Pfizer as the total sum expended in providing treatment, compensation and support for the victims of the test. An additional $450 million is requested for “public enlightenment efforts to erase societal misgivings and prejudices that arose from the test.”

The plaintiff demands $1 billion as cost of its sponsored health programs and initiatives, which allegedly failed due to societal misgivings and prejudices from the drug test. Another $5 billion is claimed for general damages.

Kano State authorities have also filed a $2 billion suit against Pfizer.