A civil rights group alleges that staff at a privately run Kansas prison repeatedly disparaged a Muslim woman for wearing a headscarf and ordered her to take it off before allowing her to leave her cell.Washington-based Muslim Advocates raised concerns about the treatment of 49-year-old Valeriece Ealom in a letter to CoreCivic, the Tennessee-based company that operates the prison in Leavenworth. The letter, which was made public on Wednesday, also was sent to the US Marshals Service, which contracts with CoreCivic to house federal prisoners, The Kansas City Star reports.CoreCivic did not immediately respond to questions from The Star or The Associated Press. A spokesperson for the US Marshals Service says they are looking into the allegations.Ealom has been held at the Leavenworth Detention Center since last November after federal prosecutors moved to revoke her parole in a drug case. The letter said she "believes it is her fundamental obligation to practice modesty by wearing a headscarf," which a prison chaplain provided.But when other employees allegedly harassed Ealom about wearing it and threatened to discipline her if she did not take it off, Ealom filed a formal complaint. The letter said that only made the harassment worse and that at one point an officer confiscated her scarf as "contraband." She alleged that at other times, a guard has interrupted her prayers to conduct searches of her cell.The letter said the prison's management has "failed to take any meaningful correction action" and that the Marshals Service has "permitted this harassment to continue".In February, acting without a lawyer, Ealom filed a federal civil lawsuit over her treatment. A judge dismissed the suit in June, saying that it didn't provide enough information to show how she had been harmed.Leavenworth Detention Center has faced many complaints in recent years. The prison is the focus of ongoing legal action over the taping of phone calls between prisoners and their lawyers. A Justice Department audit last year blasted the prison for understaffing, security problems and deceptive practices. Prison officials have been accused of retaliating against employees who complain.