According to the chief administrator for the Bilaspur district Siddhartha Pardeshi, preliminary tests of the antibiotic Ciprocin tablets given to over a dozen women who visited the sterilisation camp in Chhattisgarh, contained zinc phosphide, a chemical compound commonly used in rat poison. The zinc phosphide was found at the nearby factory of Mahawar Pharmaceuticals, the firm at the centre of the investigations into the deaths at the camp. The antibiotics were given out at the mass sterilisation held in the impoverished state where at least 15 women have died. Samples of the drugs have now been sent to laboratories in Delhi and Kolkata to verify that the tablets were contaminated. Mahawar Pharma had earlier been barred from manufacturing drugs for 90 days in 2012, after it was found to have produced sub-standard drugs. It did not lose its licence however. The state government said it has seized 200,000 tablets of Ciprocin 500 and over 4 million other tablets manufactured at Mahawar and the firms managing director Ramesh Mahawar and his son have been arrested. They both say they are innocent.