Up to 38 girls may have been victims of a child prostitution ring in Oxford, a court has heard.
Six men have been charged as part of an investigation into child exploitation and trafficking. Another seven were bailed until next month.
Police previously said 24 girls had allegedly been targeted.
The six men face charges including rape, conspiring to rape a child, arranging child prostitution and trafficking.
Zeshan Ahmed, 26, Mohammed Karrar, 37, Bassan Karrar, 32, Kamar Jamil, 26, Anjum Dogar, 30, and his brother Akhtar, 31, appeared at Amersham Crown Court yesterday.
They were remanded in custody and are due to enter pleas on 22 June.