20/ Guidelines on the conditions of arrest, police custody and pre-trial detention in Africa in a manner consistent with the Guidelines and Measures for the Prohibition and Prevention of Torture, Cruel, Inhuman or Degrading Treatment or Punishment in Africa. b. If there are reasonable grounds to believe that an act of torture and other cruel, inhuman or degrading treatment or punishment, or another serious human rights violation has taken place, States shall ensure prompt investigation by independent and impartial authorities.