The suspects were held this morning as part of a child exploitation investigation into the cases of 24 girls aged between 11 and 16 in Oxford. The men - aged between 21 and 37 - are now being questioned on suspicion of a string of offences including causing the prostitution of young girls, trafficking, grooming and rape. They are being held in custody at an undisclosed police station. The alleged offending is believed to span more than a six-year period. Detective Superintendent Rob Mason, of Thames Valley Police, said: ''We believe we have uncovered an organised crime group who have been running a business of selling young girls for sex.