The U.S. Food and Drug Administration said it is continuing its investigation into possible quality control issues at Mylan Inc.'s (MYL) Morgantown, W.Va., manufacturing facility, contrary to a statement made by the generic drug maker earlier Tuesday.

In response to the FDA statement, a Mylan spokesman said "our CEO would never have gone out with a statement like that without being informed of the closeout of the FDA inspection."

Officials from the FDA weren't immediately available to respond to Mylan's latest comments.

"This investigation involves allegations of compliance violations that the FDA takes very seriously," Steven Solomon, FDA's Assistant Commissioner for Compliance Policy in the Office of Regulatory Affairs, said in a statement Tuesday.

"The investigation is on-going and the agency has formed no conclusions at this time. Statements to the contrary are untrue," he said.

Earlier Tuesday, the company had issued a press release saying the FDA had visited the manufacturing facility on Monday and determined that "the baseless accusations in the article were unfounded."

Shares of Mylan dropped after the FDA's comments, recently trading up 3.3% to $12.50 on more than four times regular trading volume. The stock traded as high as $13.37 earlier Tuesday after dropping 12.6% on Monday, following a Pittsburgh Post-Gazette story Sunday.

The newspaper reported that Mylan had launched an internal probe to investigate whether workers at the plant had been routinely overriding computer-generated warnings about the drugs being produced at the plant. The newspaper cited an internal report and had other experts review the report and call it a significant problem.

Mylan said Monday that the issue had "no impact on the quality of our product."

Tuesday, Mylan said the agency "noted there was no evidence of any data deletion. All data was reviewed and was present and accounted for."

-Thomas Gryta; Dow Jones Newswires; 212-416-2169; thomas.gryta@dowjones.com