Update 4:50 p.m.: White House spokesperson Josh Earnest disputed the claim, "Based on the information that has been provided to me, I don't believe that is accurate." Barfi has not yet again commented on the matter.

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Speaking with Anderson Cooper on Monday, the spokesman for Steven Sotloff's family said that the journalist, who was beheaded by Islamic State fighters last week, was believed to have been sold to the group by Syrian rebels for as much as $50,000.

In the interview, a very outspoken Barak Barfi cited "sources on the ground" for the new revelations about Sotloff's kidnapping.

We believe that these so-called moderate rebels that people want our administration to support, one of them sold him probably for something between $25,000 and $50,000 to ISIS, and that was the reason he was captured."

He added that it was believed that Sotloff had been lured to a fake checkpoint after he crossed the border into Syria where ISIS captured him.

The interview took a combative turn as Barfi also blasted the Obama administration for "inaccurate statements" about the nature of Sotloff's disappearance, referencing the ordeals of both Sotloff and James Foley, who was beheaded last month by ISIS.

We know that the intelligence community and the White House are enmeshed in a larger game of bureaucratic infighting and Jim and Steve are pawns in this game and that's not fair and if there continues to be leaks the Sotloff family will have to speak out to set the record straight."

As his critics continue to hammer him on foreign policy, President Obama's approval rating has dropped to new lows, a development that dovetails with a surge of approval for American airstrikes against ISIS, which the president has both endorsed and executed.

After its execution of two American journalists, support for air strikes against ISIS in Iraq has swelled from 45 percent in June to 71 percent now. Support for arming their Kurdish opponents is up by 13 points, to 58 percent, in just the past month.

President Obama is set to address the nation tomorrow to outline his plan to combat ISIS going forward.