These included the use of dangerous restraint techniques where people were handcuffed with their hands behind their backs while seated, and the application of pressure to a detainee’s neck while he was in extreme distress.
The inquiry heard evidence of a toxic culture among G4S staff, racist and derogatory language, poor safeguarding and excessive use of force.
The inquiry, chaired by Kate Eves, made 33 recommendations for urgent change.
Eves said: ‘That I found this number of incidents took place within such a limited timeframe of five months is of significant concern. An environment flourished in which unacceptable treatment became more likely.’
The inquiry was commissioned by former home secretary Priti Patel, following a BBC Panorama report.