A social worker from Texas who was detained in a Mexican prison for delivering Christmas presents was released on Christmas Eve.

Anamichelle Castellano and another volunteer woman were delivering gifts to children living in makeshift migrant camps from Brownsville into Matamoros, Mexico, on behalf of Castellano’s NGO Socorro Foundation Monday before their arrest.

They brought a car packed with over 300 gifts in what was one of their routine trips there. While the car was put through an x-ray machine in security checking, a small box of bullets came into view. Mexican authorities immediately took Castellano and her aid into custody. Castellano’s parents, in a brief call with her Tuesday afternoon, learned that she had been charged with possession of ammunition. They were, however, released later that night.

Anamichelle's husband, Jehu Castellano, and their nine-year-old daughter, who were also there in the next car, witnessed the arrests and waited in Matamoros until she was released.

The bullets were allegedly leftovers from Jehu's hunting trip which he had forgotten to remove from the car. Her family said Mexican police and attorneys had been making a slew of threats.

"(They are) kind of threatening her with federal prison, federal this and federal charges and we believe this is all a big set up where they're trying to see what they can get out of it," Genaro Lopez, Castellano's father, told ABC 7.

"I mean, this is Santa Clause coming in to give toys to the unwanted and you're doing what? You're doing what? You're threatening her for what?" he added.

Jehu approached a prosecutor in Matamoros for help who he said asked the exorbitant amount of money.

The refugee camps are home to many U.S. asylum seekers under the onslaught of President Donald Trump’s hardline approach to immigration. Many of them have been deported back to Mexico as part of the Migrant Protection Protocols (MPP) policy which started this year.

Refugees wait to board buses after their arrival from Lesbos to the port of Piraeus near Athens
Refugees wait to board buses after their arrival from Lesbos to the port of Piraeus near Athens AFP / LOUISA GOULIAMAKI