The US Food and Drug Administration is inspecting Dr Reddy's research and development centre in Hyderabad, the pharma company said on Tuesday.
"We confirm the commencement of a USFDA inspection at our R&D centre (Integrated Product Development Organisation or IPDO)," a Reddy's spokesperson told Reuters.
A unit of Laurus Labs' subsidiary Laurus Synthesis in Vizag, Andhra Pradesh, is also being inspected by the US drug regulator, according to a source familiar with the matter.
Rivals Sun Pharma's Dadra facility and Torrent Pharmaceuticals Ltd's oncology unit are also undergoing FDA inspections, CNBC-TV18 reported.
Sun Pharma, Laurus and Torrent did not immediately reply to Reuters' requests seeking comment.
Torrent Pharma closed 1.6% lower following the news, while Laurus Labs ended 0.9% down. Sun Pharma and Dr. Reddy's settled 0.7% and 0.4% higher, respectively.
(Reporting by Rishika Sadam in Hyderabad, Kashish Tandon in Bengaluru; Editing by Sonia Cheema and Sohini Goswami)