Published: Oct 01, 2012 10:05 PM EDT
Updated: Oct 02, 2012 7:29 AM EDT

LEE COUNTY, Fl. - Court documents reveal how a trip away from home turned into a nightmare for a four year old girl.

Investigators are calling it one of the worst cases of child porn they've ever seen.  Registered sex offender, Alan Johnson and girlfriend Jennifer Sparks are accused of molesting a 4-year-old girl and using her to create child porn.

Documents show the little girl lived in Orlando with her mom.  The mother was friends with Sparks.  On May 15th, the mother reportedly allowed the couple to take the little girl to their Fort Myers home.

The little girl stayed for several weeks.  Documents show the mother was having problems with her sister and did not want the child around.  At the end of the third week, Sparks said the brakes on their van were out and they couldn't drive the girl home.  That's when the mother says she became suspicious the couple was trying to keep the girl.

The documents reveal Johnson had a website where he sold adult toys and pornographic movies.  Authorities also uncovered several laptops, cell phones, cameras and USB drives, all of which contained hundreds images and videos of Johnson and Sparks molesting the young girl.

Investigators say some of those graphic images they found contained pictures of several other unidentified girls and boys.  Johnson and Sparks are still behind bars at the Lee County Jail.