The Central Bureau of Investigation (CBI) carried out simultaneous raids on some government hospital doctors and pharmaceutical companies in Delhi and three other cities on Monday.
The raids were conducted in Chennai, Goa, and Thiruvananthapuram, besides the national capital, an official of the investigating agency said.
The houses of Sudha Talan, head of Safdarjung Hospital's gynaecology department, and Uma Goel of Sucheta Kriplani Hospital here were searched, he said.
"The raids are being carried out after receiving several complaints against these people," the official said.
"The health ministry lost around Rs 50 million ($1 million) due to malpractice by these doctors," he said.
CBI officials said two offices of Mester Pharmaceutical Company here were also being searched.