Birth certificates, food stamps, fake identification cards and sexual services are reportedly being sold across the Texas border through Facebook, with an apparent attempt to sell a young child's birth certificate currently being investigated by authorities.

Multiple Facebook groups, identified as La Pulga Online (No Rules), La New Pulga Online, Las Milpas FB Estate Saale, and RGV Flea market, encourage and allow members to post several different illegal items for sale across the Texas border, Breitbart reported. In recent times, borders have come to be known as popular destinations to pick up personal fake documents.

Although a majority of the items for sale are listed as garage sales and other dealings, various individuals have started to advertise all sorts of government documents and other illicit activities on these social networking pages.

In some of the recent Facebook postings, Xanax pills, marijuana, cocaine, human smuggling and other border illicit activity are listed to be on sale at the Texas border.

In one instance, an unidentified woman was attempting to sell a birth certificate and social security card belonging to a 4-year-old girl in the border city of Brownsville.

After police authorities picked up signals about the Facebook post, they visited the address listed on the girl's birth certificate to investigate, according to a local TV station named KRGV

Over there, the girl's grandparents confirmed that the name and address listed on the birth certificate was their daughter's and the birth certificate belonged to their granddaughter.

On Dec. 20, detectives questioned Arcelia Vaughn and her husband on whether they had any involvement in the illegal selling of their granddaughter's documents online. After they rejected the claims, investigators compared the backgrounds of the posted photos to verify its authenticity.

"They're checking about the floor, the color of the floor because they say they don't look the floor like mine. Mine is beige and the floor is brown," said Vaughn.

For now, it remains unknown how a copy of the 4-year-old's birth certificate ended up being sold online, the girl's relatives told KRGV.

The disturbing trend of selling illegal items on Facebook has been on the rise, said Erasmo Castro, a Texas border citizen who has been consistently exposing the practice.

In an effort to halt such practices, Castro regularly submits photos of the Facebook posts to Brownsville Police and other agencies. However, the citizen journalist's action has also made him a target of many insults, with some even threatening to file lawsuits against him.

Meanwhile, the woman who posted the document for sale has since taken down her Facebook page.