Drug maker Ranbaxy's Japanese promoters on Wednesday blamed the company's former Indian owners for concealing and misrepresenting critical information about US investigation into sale of adulterated drugs, and said it will pursue legal remedies.

"Daiichi Sankyo believes that certain former shareholders of Ranbaxy concealed and misrepresented critical information concerning the US Department of Justice (DOJ) and FDA investigations. Daiichi Sankyo is currently pursuing its available legal remedies," Daiichi Sankyo said in a statement.

The Japanese drug maker added that it continues to support Ranbaxy in its efforts to address and correct the conduct of the past which led to the investigations.

Ranbaxy became a part of the Daiichi Sankyo Group in 2008 after Japan's third largest drug-maker bought a majority stake in the Indian firm. Daiichi had bought 34.82 percent stake in the Gurgaon-based firm from its promoters, Malvinder Singh and family.

Last week, pleading guilty to "felony charges" relating to manufacture and distribution of certain adulterated drugs made at two India units, the US subsidiary of Ranbaxy had agreed to pay USD 500 million in settlement with the US authorities.

The generic drugs at issue were manufactured at Ranbaxy's facilities in Paonta Sahib and Dewas in India. In 2008, the USFDA had banned 30 generic drugs produced by Ranbaxy at its Dewas and Paonta Sahib units, citing gross violation of approved manufacturing norms.

Meanwhile, Ranbaxy today said that it has taken several steps in recent years, including investment of USD 300 million across manufacturing facilities to ensure safety and efficacy of its products in the global market.

"In recent years we have made significant improvements in the way we conduct our business to ensure greater quality control and have made investments of over USD 300 million in our manufacturing facilities to install state-of-the-art technologies," Ranbaxy CEO and Managing Director Arun Sawhney said in a statement.

Sawhney said that Ranbaxy is a different company today.

"The steps we have taken over the recent years reflect the wide-ranging efforts of the current board and management to address certain conduct of the past and ensure that Ranbaxy moves forward with integrity and professionalism in everything we do," he added.

Ranbaxy said it has taken several actions including, upgrading its business and manufacturing processes and building a culture of accountability and excellence across all levels of the organisation.

The company has reconstituted the Board of Directors and executive management team since the acquisition of a majority stake in Ranbaxy by Daiichi Sankyo in 2008, it added.

Ranbaxy shares closed at Rs 431.10 on the BSE, down 1.20 percent from previous close.

PTI