The securities market regulator said Tuesday that it would file a complaint against Celltrion chairman and CEO Seo Jung-jin with the prosecution for fraudulent equity trading.

Senior regulatory officials reached a final consensus that Seo had manipulated stocks of the biopharmaceutical firm, according to the Securities and Futures Commission.

In addition, Seo was found to have exploited insider information after Celltrion drew wide attention from investors by becoming No. 1 by market capitalization among firms registered on the secondary KOSDAQ.

Celltrion has continued to deny the allegations over the past few months. The firm said in a statement in September that it notified financial regulators of its stance that “we were not implicated in any irregular use of insider information and did not take any illicit gains.”

Earlier this year, Seo said that he was tired of the speculative attacks on the company stocks from hedge funds.

He had also argued that regulators had been “negligent” in the oversight of stock scammers.

Despite uncertainty over fate of the company owner, stock prices of Celltrion closed at 46,150 won ($42) earlier in the day, up 5.61 percent from a trading session earlier.

By Kim Yon-se (kys@heraldcorp.com)