As Artificial Intelligence (AI) increasingly powers autonomous offensive security tools (i.e., AI Pentesters); ensuring their operational integrity, regulatory compliance (e.g., under the EU AI Act), and ethical conduct becomes critical, particularly when direct human oversight is limited or absent. To address these challenges, we propose an Intelligent Assurance System (IAS) that provides continuous oversight and accountability for fully autonomous AI Pentesters. The IAS is designed to enhance trustworthiness by monitoring execution traces, enforcing compliance, delivering real-time feedback, and facilitating self-improvement while being resource-efficient.