A Minnesota woman is speaking out against Delta Airlines, claiming her puppy was held in custody for more than 33 hours over paperwork that airline officials misplaced.

Mary Nguyen, a 25-year-old student in Minneapolis, recently shipped her 8-month-old German Shepherd, Bunny, to live with her husband in Guatemala. Nguyen told CBS News that officials at La Aurora International Airport in Guatemala City had all the required paperwork they need to release the dog from custody but refused to do so.

"They have all the documents they need on their scratch pad to release her but refuse to do so without the hard copy that they lost [but tracked down]," she said Friday evening. "The document has been in their possession the whole [time] since I've surrendered my dog over."

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Later Friday night, the puppy was released, Nguyen told MarketWatch.

Bunny Courtesy of Mary Nguyen

Nguyen told MarketWatch she had paid Pet Air Carrier $3,000 to transport Bunny on a Delta flight and drove to Wisconsin to have the paperwork endorsed. But Delta Airlines in Guatemala demanded an additional $3,000 before her husband could take the dog home.

She told the outlet she was dealing with a "hostage situation" before Bunny's release.

"After 33 hours, they finally released Bunny," she told MarketWatch.

In a statement to CBS News, a Delta spokesperson said the airlines would be refunding the cost of shipment while new paperwork was sent to Guatemala: "We know that pets are important members of the family and are working directly with the customer."