Prisoner and free-speech advocates are demanding a written guarantee that inmates at a Virginia jail can receive letters containing religious material after a prisoner said his mail was censored.

The American Civil Liberties Union, its Virginia chapter and several other civil, religious and prisoner rights organizations sent a letter to Rappahannock Regional Jail Superintendent Joseph Higgs Jr. requesting that the issue be resolved without litigation.

Anna Williams, whose son was detained at the jail for several months, said officials cut out entire sections of several letters she sent to her son that contained Bible verses or religious material. She said the jail cited prohibitions on Internet material and religious material sent from home.

“Obviously for security issues the right to practice religion while incarcerated is a balancing act to some extent, but that can’t possibly apply to a mother sending religious passages to her son,” said Kent Willis, executive director of the ACLU of Virginia.

Higgs said in a written statement that the letter prompted him to initiate an internal investigation.