After rising 15 per cent Wednesday, the Ranbaxy stock resumed its downward journey on reports in the US media that a US Congressional Committee will examine Ranbaxy's drug approvals in the US and potential violations of manufacturing regulations. The committee will also scrutinise the US drug regulator Food and Drug Administration's (FDA's) role in approving products of the Indian drug major. The company's share price plunged 4 per cent today on the Bombay Stock Exchange (BSE) on a day the 30-share Sensex rose 536 points. This is despite a press release issued by the company this morning to reassure investors on the company's quality standards and a clarificatory media briefing yesterday by Managing Director and CEO Malvinder Singh. "We are not aware of any congressional committee inquiry and have not received any communication in this regard," a Ranbaxy spokesperson said in an e-mail response. "Ranbaxy is a highly regarded company that has always believed in upholding the highest standards of quality. All our plants produce medicines that meet global norms," the spokesperson added. The media reports said the House Energy and Commerce Committee will look at why the FDA continued to approve medicines made by the company and allowed shipments into the US while it was questioning Ranbaxy's manufacturing processes. The report also said the Committee wants to find out whether the FDA knowingly allowed unsafe and ineffective medicine to enter the US. "If these allegations are true, Ranbaxy has imperiled the safety of Americans in a manner similar to the generic drug scandal we uncovered 20 years ago," a newspaper report quoted House Energy and Commerce Committee Chairman John Dingell as saying. A joint press release issued in the morning by Ranbaxy and Daiichi Sankyo reiterated that the agreement between the Japanese company, Ranbaxy and the Singh family, was binding and final, subject to regulatory approvals. The US government had approached the District court of Maryland on July 3, demanding that Ranbaxy submits crucial data on an ongoing investigation into the sale of sub-standard drugs in the US market. Ranbaxy has clarified that it will submit the data demanded by the regulator and would co-operate with the US FDA and Department of Justice in all respects related to the investigation.