Ranbaxy Laboratories, manipulated data and laboratory tests for generic drugs that had been approved for sale in the United States at its Himachal Pradesh facility.
The FDA disclosure marks completion of the first phase of a probe it had begun soon after Japanese drug major Daiichi Sankyo entered into an agreement with Ranbaxy's promoters to acquire majority shares in the company for over four billion dollars, becoming Daiichi subsidiary in November 2008.
The FDA cited the fraudulent laboratory tests on Wednesday as it took the unusual step of stopping its review of all pending applications from Ranbaxy Laboratories, the Washington Post reported.
Federal investigators said the problems centered on the company's plant in Paonta Sahib, which has produced 25 drugs that have been approved by the FDA.
Most of those medications are not thought to be on US pharmacy shelves; since September, Ranbaxy has been prevented from exporting more than two dozen drugs to the United States.
The FDA is not seeking a recall, because regulators do not believe the drugs pose a health risk.
"There is no concern about the safety or efficacy of Ranbaxy's drugs on the US market," said Deborah Autor, director of compliance at the FDA. The affected drugs include medications for high cholesterol and an antihistamine, but the FDA would not provide a specific list.
Patients using the drugs should not stop, said Douglas Throckmorton, deputy director of the FDA's Center for Drug Evaluation and Research.
But federal officials said they were concerned enough by their investigation into Ranbaxy's Paonta Sahib plant that they decided to halt approvals of any new or pending applications from the company.