While in the country, he met with American fugitive Dawud Salahuddin, whom the CIA was hoping to recruit as an asset, a source told Fox News at the time. After the meeting, Levinson went missing from Kish Island.

Moriarty told Martha MacCallum the Iranian government made mention of “Revolutionary Court,” which she said is geared toward criminal-type cases as opposed to those for missing persons.

She called that development a “key element” of her father’s case, and called Iran’s behavior “unacceptable.”

“We also need Americans to recognize that this is unacceptable and that Iran must send him home,” she said, urging officials in Tehran to “come clean” about what has transpired over the last 12 years.

“My message to my dad is that we are working tirelessly every day and we are working hard to bring him home.”

Last week, Secretary of State Mike Pompeo announced the State Department would offer $20 million on top of a $5 million reward already posted for information leading to Levinson’s recovery and return.

“The Trump administration has made clear that the regime in Iran must release all missing and wrongfully detained Americans, including Robert Levinson, Xiyue Wang, Siamak Namazi, and others,” Pompeo said in a statement. “We will not rest until they are reunited with their families.”

Fox News’ Brie Stimson contributed to this report.