Story highlights Video of cash delivery purportedly aired on Iran TV in January

The latest wrinkle is bound to fuel critics of the administration

Washington (CNN) A video emerged Friday that purportedly shows a US payment of $400 million worth of cash delivered to Iran on the day Tehran released several American prisoners in January.

CNN cannot authenticate the newly surfaced video, which was part of an Iranian documentary that first aired in January and shows the money on pallets in a warehouse. But the latest wrinkle is bound to fuel critics of the administration who have accused Obama of providing ransom to the Iranian government in exchange for the release of four US prisoners. A fifth American was released separately.

The Obama administration has vehemently denied any connection between the cash delivery and the release of the American prisoners.

"We announced these payments in January. Many months ago. They were not a secret," Obama told reporters at the Pentagon Thursday.

"It was not a nefarious deal," Obama said, adding, "We do not pay ransom for hostages."

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