Possible Clues:

• Goes off, having installed bug for secret police
• Extreme force set to work, filling hole on roof of office
• Abnormal postage brings out the secret police
• Try to conceal evidence at first, with criminal past in state police
• Brutal force has to work, a pest breaking and entering
• Leave, receiving directions to bug secret service
• Old force associated with police organisation known by its letters and odd postage
• "The Diary of Anne Frank" police
• Ruthless organization
• Dictator's henchmen sorting postage