G4S faces further investigation over its management of Brook House, near Gatwick Airport. : The director of a G4S-run immigration centre where staff were filmed abusing and humiliating vulnerable migrants has resigned as the controversial security firm faces further investigations. Ben Saunders left his role at Brook House, near Gatwick Airport, with “immediate effect” three weeks after the scandal broke. Jerry Petherick, the managing director for G4S Custodial and Detention Services, said an interim director would be put in place before the appointment of a replacement.