Ranbaxy Laboratories — India's biggest drug maker and one of the largest generics firms in the world — has been slapped with tough penalties by the US Food and Drug Administration (FDA) after it was caught repeatedly falsifying data from one of its four Indian manufacturing plants.

The FDA action revokes some 25 existing approvals of drugs made at Ranbaxy's factory at Paonta Sahib in Himachal Pradesh, and stops an unnamed number of pending applications for drugs from the same plant.

Details released by the agency on 25 February reveal that, since at least 2006, Ranbaxy employees refrigerated samples that were supposed to be stored at room temperature to test their stability over time. In another instance, the plant misreported stability test results that were conducted over days instead of months.

The company issued a written statement saying that it "will continue to cooperate" with the US agency.