CNN unravels the 'mind numbing' source of Trump's latest Obama conspiracy
Donald Trump at at Trump International in New Jersey (Shutterstock)

CNN on Wednesday explained the source of President Donald Trump's latest unsubstantiated attack on former President Barack Obama.

Trump tweeted on Tuesday morning that the Obama administration had granted citizenship to 2,500 Iranians as part of the nuclear deal.

CNN's Oliver Darcy said Trump's allegations appeared to have originated with an Iranian newspaper, which cited a cleric. The claims were later picked up by Fox News.

"The great thing is Fox News' own commentator [former Obama State Department spokeswoman Marie Harf] told Fox News this sounds like BS. That's an actual quote they included in their story and Fox News still ran with it, which is just really mind numbing," he added.

Watch video below: