A former spokesman for Hillary Clinton's campaign said he doesn't know if the failed presidential candidate knew her campaign was funding opposition research that resulted in the controversial Russian dossier about President Trump.

Brian Fallon told CNN he hadn't spoken to Clinton about the dossier and isn't sure if she knew exactly how involved her campaign and the Democratic National Committee were in funding Fusion GPS' work. That firm funded Christopher Steele, a former British spy, as he investigated Trump's business interests in Russia that ended up in a salacious document with many unconfirmed details.

"Oh I don't know, I don't know, I haven't spoken to her," Fallon said, when asked if Clinton knew about the research.

"She may have known, but the degree of exactly what she knew is beyond my knowledge. For instance, it could have been a decision was made to authorize to do some kind of commission, some kind of research, but then decisions about, you know, going out and finding Fusion GPS, finding Christopher Steele. I mean, she may or may not have been aware of that level of detail. I don't know."

Fallon said he never personally saw the dossier before the election and only became aware of it when reporters began calling and asking about it in the month leading up to the election.

Buzzfeed made the controversial decision to publish the dossier in full before Trump was sworn in as president, despite not being able to confirm much of the document.

Fallon said he thought the information in the document was just opposition research done by Trump's opponents in the GOP primary that had "gone dormant" and was resurrected when the intelligence community said Russia was trying to interfere in the election.

"It resurrected a lot of interest with trump's calls with Russian. So when those calls would come in, we found it interesting, we would trade information about what we were hearing from different sources," Fallon said. "But, we were powerless to help those reporters get over the hump and get over the finish line of reporting, because we didn't have any of the research or at least I didn't have it directly."

Fallon said it's not a big deal that Democrats and the Clinton campaign funded the research because it's standard practice in a campaign to get opposition research on an opponent — a line that's very close to what Trump supporters said after it was revealed Donald Trump, Jr. took a meeting with a Kremlin-linked attorney promising dirt on Clinton.

However, Fallon said the two cases were different.

"The Russians and Vladimir Putin were only trying to help one side in this election," he said. "And, you don't have to take my word for it on that. That is the conclusion of U.S. intelligence."