A stolen picture of Britney Spears’ teenage sister Jamie Lynn breast-feeding her daughter has prompted a federal pornography investigation.

According to the US Gossip website TMZ, federal and local authorities are on the look out for the man who tried to sell 12 family pictures.

The pictures include shots of the teen mother and elder sis, Britney, originally taken by the infant’s father, Casey Aldridge.

Aldridge took pictures in the memory card so that they could be developed at his local Wal-Mart in Louisiana, reports The Sun.

However, authorities believe that a Wal-Mart employee made extra copies and then tried to sell them.

One of the pictures exposes the left breast of Jamie Lynn feeding her daughter, Maddie.

Since Jamie is a minor, selling her exposed pictures—or buying them—could violate federal laws that prohibit pornography