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Washington — CBS News has confirmed a Russian disinformation campaign helped push a bogus theory that Hillary Clinton's presidential campaign paid to murder a Democratic National Committee staffer. Police believe the 27-year-old victim Seth Rich was killed after an attempted robbery, three years ago in Washington.

Details of Russia's involvement are outlined in a new report by Michael Isikoff of Yahoo News, who spent a year investigating.

"We found that Russian trolls in St. Petersburg tweeted and retweeted about Seth Rich more than 2,000 times," he said.

The story resonated with conservative commentators and Russian media outlets. It also found its way to the White House. Steve Bannon, a former senior adviser to President Trump, in March 2017 texted a "60 Minutes" producer about the Rich case, calling it a "huge story" and claiming that "it was a contract kill, obviously."

Seth Rich

The "60 Minutes" producer said Tuesday that it had received the texts, but never pursued the story. The theory has been debunked by local police and the FBI.

"It shows just how easy it is to manipulate news in this era of social media," Isikoff said. "Anybody [who] wants to manipulate American public opinion, planting phony stories on social media, is the way to do it."

Rich's murder and the conspiracy around it even ended up in special counsel Robert Mueller's investigation of Russian election meddling. The case remains unsolved — one of more than 200 unsolved murders in Washington since he was murdered.