Barbero was last seen leaving his home in Spain on Tuesday.
WSBTV first broke this story last month, with the original video that animal activists claim shows Barbero hitting and kicking dolphins.
In February, Georgia Aquarium CEO Mike Leven said, "We want Jose Barbero to get fair treatment, a fair judgment, and we will stand behind him until this video is proven to be true or false."
Aquarium leaders confirmed it hired consultants to analyze the video, and to see if it's authentic. A former FBI agent hired by the aquarium traveled to Spain as part of his investigation.
Leven also told Diamant that Barbero received death threats once the video surfaced.
After receiving the news about his disappearance Leven sent Diamant a statement that read, "We are very concerned. We hope he turns up soon and that everything is all right. Our thoughts are with him and his family."
Barbero was supposed to start work at the Georgia Aquarium the first week of March.
In a statement, Georgia Aquarium CEO Mike Leven said:
"It was with sadness, outrage and frustration that I received the news this morning that Jose Luis Barbero was found dead in Spain. Initial reports suggest that he allegedly ended his own life. He was a husband, a father and a grandfather who dedicated nearly four decades to caring for animals. We at Georgia Aquarium were proud to have had him serve periodically as a consultant to our organization over the past eight years. His service with us was exemplary.
"After allegations were levied against him, we took the situation very seriously. Georgia Aquarium began a search for truth in hopes of disproving these unsubstantiated claims. Sadly, he and his family received death threats, and groups and individuals rushed to judge him. He was not given the right or the privilege to be considered innocent until proven guilty, a principle I hold dear. His death is untimely, unnecessary and unjust.
"We were not given the chance to thoughtfully and thoroughly review the allegations against him before activists, consultants and some in our own community tortured him with enough hatred to cause him to allegedly take his own life. I hope the death of Jose Luis Barbero teaches those who were quick to condemn him a lesson about being hasty to charge and indict.
"We will continue to operate Georgia Aquarium with dedication, devotion and pride in how we care for and about our animals -- as well as the people affiliated with our organization. We will continue to serve the community and be advocates for animals around the world, as we have done since our founding. We will never condone any injustice, such as the one done to Jose Luis Barbero.
"We mourn with his family, his friends and all those who must contend with this terrible loss."