HOUSTON — 597 days have passed since six Citgo executives boarded a plane Nov. 21, 2017 at Sugar Land Regional Airport for an emergency budget meeting in Venezuela.

RELATED: 'We are fearful' | Family members plea with leaders to help release 'Citgo 6'

The government of Venezuelan President Nicolas Maduro arrested the men on charges of corruption and embezzlement stemming from a $4 billion agreement to refinance company bonds.

Jorge Toledo, Tomeu Vadell, Jose Pereira, and brothers Jose Luis and Alirio Zambrano never came home. Until this week, their families knew they were in a Caracas prison, but in April, the Citgo six stopped calling home. Jail employees on Wednesday denied their lawyer their weekly visit, and the families are being told their fathers may have been relocated.

“Their location to us is unknown,” said Gustavo Cardenas, whose father shares the same name. “Their condition is unknown. We have no way of knowing what’s happened to them, and that’s especially worrying when people have already died in that building.”

The Cardenas mark each passing day on a kitchen calendar to keep track of how long their patriarch has been in prison.

“This is the first time we’ve been unaware of their condition for more than a couple days,” Cardenas said.

Each of the Citgo six families are demanding the Venezuelan government provide proof of life. However, they can only lean on lawmakers for help freeing their family.

In February, Senators Ted Cruz and John Cornyn both told KHOU 11 they’re working on their safe return.

Citgo released the following statement:

“Like their families, we are deeply concerned about our former executives who are detained in Venezuela, and more so now that reports indicate they have been moved to an undisclosed location with absolutely no contact with their families. As a company, we believe that all persons’ fundamental human rights must be respected. We offered our support to the State Department immediately upon learning of the detention, and we have never wavered in our offer to assist the U.S. Government as best we can. Additionally, we have provided health care coverage to the families of the detainees and recently, the board of directors offered assistance with legal fees for them, as well. We have also been engaged with their legal teams for some time and continue to engage in those discussions to date. We pray for their safety and for their families who desperately wish to hear from their loved ones.”

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