OSAKA -- A former senior prosecutor who blew the whistle on alleged corruption among fellow prosecutors pleaded not guilty on Tuesday to charges of taking bribes and abusing his authority.

In his first hearing at the Osaka District Court, Tamaki Mitsui, a 58-year-old former official of the Osaka High Public Prosecutors Office, denied receiving entertainment from gangsters in exchange for internal information.

"I never committed a crime. Criminal activities lie with the prosecutors who have indicted me," Mitsui said, asking the court to dismiss the charges against him.