While she was secretary of state, Hillary Rodham Clinton wrote and sent at least six e-mails using her private server that contained what government officials now say is classified information, according to thousands of e-mails released by the State Department.

Although government officials deemed the e-mails classified after Clinton left office, they could complicate her efforts to move beyond the political fallout from the controversy. They suggest that her role in distributing sensitive material via her private e-mail system went beyond receiving notes written by others, and appears to contradict earlier public statements in which she denied sending or receiving e-mails containing classified information.

The classified e-mails, contained in thousands of pages of electronic correspondence that the State Department has released, stood out because of the heavy markings blocking out sentences and, in some cases, entire messages.

The State Department officials who redacted the material cited national security as the reason for blocking it from public view.