Victims of disgraced sports doctor Larry Nassar are imploring Texas authorities to investigate whether Bela and Martha Karolyi could have done more to prevent Nassar's sexual abuse at the couple's Texas training center.

Five former gymnasts, including two who say Nassar abused them at the Karolyis' ranch near Huntsville, addressed reporters Thursday outside state Attorney General Ken Paxton's office.

They say Texas authorities have focused on Nassar, now imprisoned for life, while overlooking whether the Karolyis could have prevented abuse. Martha Karolyi told "Dateline NBC" last month that Nassar conned her and her husband in much the same way he conned the parents and coaches of the girls he abused.

The Texas Rangers are investigating, but the gymnasts say Texas hasn't executed search warrants or secured indictments, as some statutes of limitation loom.

Olympic bronze medalist Jamie Dantzscher, who says Nassar molested her at the ranch, said: "I can't understand why this is not taken seriously in Texas."