The family of a former FBI agent who disappeared while on a business trip in Iran a decade ago filed a lawsuit on March 21 demanding damages for the abduction and torture of their relative.

The lawsuit, filed in a U.S. federal court, includes information about Iran’s willingness in the past to release Robert Levinson in exchange for a member of the Islamic Revolutionary Guard Corps who defected to the West, Reuters reported.

The suit is “against the Islamic Republic of Iran (‘Iran’) under the Foreign Sovereign Immunities Act… for injuries suffered by [plaintiffs] as a result of Iran’s unlawful acts of hostage taking, torture and other torts.”

It states: “Iran has, for many years, established a pattern of seizing and holding hostages in order to extract concessions from the hostage’s home country. That Robert Levinson’s seizure is a part of that pattern is reflected in Iran’s multiple attempts to use Robert Levinson’s imprisonment to extort concessions from the United States.”

The lawsuit seeks unspecified monetary damages from Iran.

Levinson disappeared from Iran’s Kish Island on March 9, 2007. U.S. officials for many years would only say that Levinson, who formerly worked as an investigator for the FBI, at the time was working in the private sector.

In December 2013, The Associated Press reported that Levinson had actually been on a mission for CIA analysts and that Levinson’s family had received a $2.5 million annuity from the CIA in order to stop a lawsuit revealing details of his work. Meanwhile, CIA forced out three veteran analysts and disciplined seven others, the AP reported.

Fox News interviewed Levinson’s son Daniel on the 10th anniversary of his father’s disappearance and shortly after the Trump White House declared it would “spare no effort” to recover Levinson Senior or learn the full story of his fate.

Levinson reiterated his family’s criticism of President Obama for ignoring his father’s plight in favor of securing a nuclear agreement with Iran.

“[Obama] had said many times over the years that it was a top priority, but he had eight years to get him out, and he didn’t,” Daniel Levinson said.

The Levinsons, however, think their father’s fate may be better served by President Donald Trump.

“We know that President Trump has no qualms about doing that – threatening sanctions, threatening to label the Iranian Revolutionary Guard a terrorist organization,” Daniel said. “So we’re hoping that he’s going to be tough.”

CNN reported that on January 20, 2016, FBI investigators said they believe Robert Levinson, if he is still alive, is being held in Iran despite public statements from U.S officials in other agencies claiming he may be elsewhere, according to U.S. officials familiar with the investigation.

On February 11, 2016, the Senate passed a resolution recognizing that Levinson is the longest held US civilian in U.S. history and urging Iran to “act on its promises to assist in” his case.