The children of Robert Levinson, whose abduction in Iran on March 9, 2007, makes him the longest-held hostage in U.S. history, are finally seeing progress in their effort to hold the Iranian regime accountable for the disappearance of their father more than 12 years ago.

Levinson, who spent nearly three decades working for the U.S. government, including 22 years as an FBI special agent, vanished in an abduction by Iranian authorities from Kish Island. Levinson was originally believed to be in Iran as a private investigator, and the U.S. initially claimed Levinson wasn't working for the U.S. government at the time, though news outlets in 2013 revealed Levinson was part of an off-the-books CIA mission when he was captured. No photos or videos have been released of Levinson since 2010 and 2011, and Iran has offered a series of conflicting narratives denying Levinson is in their custody.

Dan Levinson, 34, and Sarah Moriarty, 39, two of Levinson’s seven children, told the Washington Examiner that November revelations from Iran about their father’s detention and strong support from the Trump administration have given them hope the Iranian regime will finally be forced to tell the truth. The family is in Washington, D.C., this week to make its case to Congress and the courts.

“It’s a very clear case at this point — and the world can clearly see — that Iran is holding him. And with all these developments going on right now and all this increased pressure, it’s all coming together that it’s time,” Dan Levinson said. “We believe that the time is right — Iran needs to come clean.”

“It’s very obvious that Iran can no longer pretend they don’t know anything,” Moriarty said. “Everybody sees this for what it really is, which is that they picked up our father. And now is the time for them to send him home.”

All 21 members of the extended Levinson family — including his children's spouses and children whom Robert Levinson has never met — are expected to appear in court on Wednesday and Thursday for the family’s ongoing civil lawsuit against the Iranian regime. Robert Levinson’s wife, Christine, and all seven of his children made declarations to the court, and all plan to testify about their father’s abduction.

Moriarty spoke on the Senate Human Rights Caucus’s “Detained in Iran” panel Tuesday.

At the start of November, the State Department announced a $20 million reward for information leading to the safe return of Levinson, in addition to a $5 million reward offered by the FBI.

“That’s on par with how much the U.S. government was offering for Osama bin Laden and ISIS leader [Abu Bakr] al Baghdadi,” Dan Levinson said. “This is a lot of money, and it shows, for us, the commitment of the Trump administration and how much of a priority our dad’s return is for them.”

A few days later, Iran seemed to acknowledge Levinson was alive and in its custody in a short filing to the U.N.’s Working Group on Enforced or Involuntary Disappearances, where the Levinson family had filed a complaint three years ago.

"According to the statement of Tehran’s Justice Department, Mr. Robert Alan Levinson has an ongoing case in the Public Prosecution and Revolutionary Court of Tehran," the U.N. stated.

“This is not a place where they investigate missing persons," Moriarty said. "This is the place where they investigate things that they accuse Americans of doing or that they accuse their own people of going against the state. The fact is, it says Revolutionary Court. And that is the key, because it means they have a case against him, and not a case about him.”

The Islamic Revolutionary Courts of Iran were established ostensibly to combat foreign threats and push back against efforts to overthrow the government, dealing with allegations of espionage, smuggling, blasphemy, and fomenting revolution. It is common for the regime to convict Westerners or Iranians with ties to the U.S. in secret proceedings, then announce them as hostages in negotiations, though for years Iran has kept mum about Levinson’s fate.

Iran quickly backtracked, with Iran’s Foreign Ministry spokesman claiming the day after the filing that Levinson is a “missing person” and “has no judicial or criminal case in any Islamic Republic of Iran court whatsoever.”

President Trump tweeted about Levinson that day, saying, "it would be a very positive step" if Iran released him.

“That was huge for us,” Moriarty said. “And we’re so thankful especially to the president’s administration and the president himself for putting such a priority on hostages and especially on our dad because they will not leave him behind.”

They said it's obvious Iran grabbed their father years ago, pointing to a since-scrubbed April 2007 article from Press TV, an Iranian government-backed outlet in Tehran, stating Levinson “has been in the hands of Iranian security forces since the early hours of March 9” and “the authorities are well on the way to finishing the procedural arrangements that could see him freed in a matter of days.”

Levinson's children also explained two newly retranslated documents, which Dan Levinson traveled to Berlin to obtain in 2010 and Moriarty called a “smoking gun” showing there’s an ongoing case in Iran against their father.

The purported Iranian arrest documents obtained by the children bolster their contention that the Iranians arrested Levinson with involvement from the Iranian security services and its judicial system. A new translation by Iranian-born Ladan Archin, a former Iran expert at President George W. Bush’s Pentagon, showed the original FBI translation was missing a few key words.

The first document, dated the day before Levinson's arrest and signed by the Iranian deputy of counterintelligence, claims that according to “security services of this Ministry in Kish” a man named “Robert Anderson” — likely Robert Levinson — “recently entered the country with a regular passport and a tourist visa." Alleging he is a spy, the document says Iranian security services should “make an arrangement to arrest him immediately by the end of the day, with the assistance of this ministry’s personnel at the headquarters of the intelligence at Kish and transfer him to a detention center with a maximum security.” The new translation shows this was a “judicial order” to be carried out by “the MOIS brothers” — agents from the Ministry of Intelligence.

The second document, dated two months later and signed on behalf of the commander of intelligence protection at Kish Air Base, describes how Levinson “expressed that he is sick,” notes “he fell into a coma,” and says a doctor “ordered to transfer him to a hospital.” The new translation reveals the Iranians again considered this part of a “judicial order” and repeatedly referred to Levinson as “the accused.”

The FBI told the Washington Examiner it is “aware of the documents, and while we cannot discuss specific details of the investigation, over the past 12 years, the FBI has worked diligently to follow every lead into Bob’s abduction.”

Levinson's children said they would keep fighting.

“I think we’ve made it very clear that we’re not going away, and it’s something that the Iranian government is going to have to address,” Dan Levinson said. “After 12 1/2 years, we’re still going as strong as we’ve ever been, and we’re keeping up the pressure.”

“We want people to be outraged along with us, that this has been allowed to go on for so long,” Moriarty said. “How can the Iranians hold someone with no access to anyone that he knows and loves for 12 1/2 years and never face any international outrage or repercussions?”