Presumptive Democratic presidential nominee Hillary ClintonHillary Diane Rodham ClintonThe Memo: Some Democrats worry rising crime will cost them The Hill's Morning Report - Presented by Facebook - Democrats await Manchin decision on voting rights bill Supreme Court battle could wreak havoc with Biden's 2020 agenda MORE's campaign manager said Tuesday it wasn't a "coincidence" that stolen Democratic National Committee (DNC) emails were released the weekend before the party's national convention in Philadelphia.
"All I know is what the experts and the reporters are telling us. What they're saying is it was likely Russian actors," Robby Mook said on MSNBC's "Morning Joe."
"I think the timing around our convention was not a coincidence," he continued.
"I find the whole picture troubling."
The FBI announced Monday that it is investigating the hack of the DNC system earlier this year, which DNC officials and security experts have attributed to Russian actors.
WikiLeaks published 20,000 emails from the committee last Friday, prompting uproar and the resignation of DNC Chairwoman Debbie Wasserman Schultz after emails showed top officials attempting to undermine Sen. Bernie SandersBernie SandersSchumer vows next steps after 'ridiculous,' 'awful' GOP election bill filibuster Schumer, Pelosi meeting with White House on infrastructure Feehery: 8 reasons why Biden should take the bipartisan infrastructure deal MORE's(I-Vt.) presidential campaign.
Mook has questioned Russian involvement in the leak, which Trump has dismissed.