Wife of missing former FBI agent Robert Levinson
Christine Levinson, wife of former FBI agent Robert Levinson, looks on as her son Daniel displays a print of his father's picture to journalists at the Swiss Embassy in Tehran on 22 December, 2007. Reuters

In an interview with CNN on Tuesday, the family of Robert Levinson urged the U.S. government to admit that the missing American worked for the CIA.

Levinson, who is now 65, disappeared from Iran seven years ago, and his family continues to express their frustration that the U.S. government has not done enough to find him. Speaking with CNN, several family members challenged the government to be transparent about the details of the case.

"I hope they are hearing our request that [U.S. government officials] acknowledge what he was doing over there and they understand that the family does want this acknowledged now," the missing man's son, Dan Levinson, said. "And we think it would be more of a positive step to getting him home."

Since his disappearance, the government has denied that Levinson worked for the government in any capacity.

"We obviously stand with the family who are the ones who live with every single day that their husband or their father isn't home with them," State Department spokeswoman Marie Harf said. "So we are using every tool at our disposal to help bring him home to his family. We can't, obviously, talk about those."

White House officials have said acknowledging Levinson worked for the government would complicate efforts to bring him home, CNN reports. But his family insists that revealing his status as a government employee is vital in the efforts to bring him home. Levinson traveled to Iran to investigate corrupt Iranian officials. He went missing soon after his arrival in the country.

In December, the Associated Press and Washington Post both reported stories saying that Levinson had traveled to Iran while working as an independent CIA contractor.