The newspaper USA Today said Friday an editor and reporter probing Pentagon propaganda efforts have been targeted by an online "misinformation campaign."
Fake Twitter and Facebook accounts have been created under the names of the reporter and editor with postings denigrating their professional reputations, according to the daily.
The timing of the online harassment coincided with stories by Pentagon correspondent Tom Vanden Brook, who has written about the military's "information operations" program that spent large sums on marketing campaigns in Iraq and Afghanistan.
The program has faced criticism in and outside the Defense Department as "ineffective and poorly monitored," the paper said.
The false online accounts, including a fake Wikipedia entry, started appearing only days after the reporter first contacted Pentagon contractors for the story, the newspaper wrote.
Two weeks after enterprise editor Ray Locker's byline appeared on a story on the same subject, a fake website under his name -- RayLocker.com -- popped up, the paper said.
A US official confirmed to AFP that the Defense Department had made inquiries to contractors doing public relations work to ask them about the false online accounts.
The contractors denied any such activity, said the official, who spoke on condition of anonymity.
But the websites were taken down following the Pentagon's inquiry. Some other accounts were removed for violating Internet providers' terms of service, USA Today said.
The Pentagon said Friday it had not launched a formal investigation of the case.
"We're aware of the allegations and are not dismissing them outright to be sure," press secretary George Little told reporters.
"We'll take a look at this story, and if appropriate, we'll take steps."
Explore further: Facebook collecting Nepal quake aid donations