Robby Mook, the campaign manager for Hillary Clinton, said Sunday that the Russians behind the recent hacking and releasing of emails from the Democratic National Committee (DNC) are doing so to help Donald Trump's candidacy, saying it was not a coincidence the emails were released right before the party's convention in Philadelphia.

CNN host Jake Tapper asked Mook about the content of the emails showing that senior DNC officials were working against Sen. Bernie Sanders (I., Vt.) during the primary. Mook said that the DNC should look into the matter and that he was confident in them doing so. Mook then accused the Russians of this hacking in order to help elect Trump, who has expressed admiration for Vladimir Putin.

"What's disturbing to us is that … experts are telling us that Russian state actors broke into the DNC, stole these emails and other experts are now saying that the Russians are releasing these emails for the purpose of actually helping Donald Trump," Mook said. "I don't think it's coincidental that these emails were released on the eve of our convention here, and that's disturbing and I think we need to be concerned about that."

Mook then accused Republicans of making their party platform more pro-Russia during the Republican National Convention.

Tapper later questioned Mook further about this, noting the seriousness of his claim.

"It is a very, very strong charge that you're leveling here," Tapper said. "You're basically suggesting that Russians hacked into the DNC and now are releasing these files through WikiLeaks to help elect Donald Trump."

"Well, this isn't my assertion. There are a number of experts that are asserting this," Mook said. "I think we need to get to the bottom of these facts, but that is what experts are telling us. Experts have said that it is the Russians that in fact went in and took these emails and then if they are the ones who took them, we have to infer that they are the ones then releasing them."