In my organization, there are 5 employees responsible for sales activities and one boss. All 5 employees are relatively new, while the boss has been working for the past 14 years. However, no junior employee has been able to stay with the company for more than a year or two. Currently, my existing team of 5 members has a strong suspicion that the boss is leaking sales inquiries to competitors, which is hindering their ability to close deals. The management shares this suspicion, but there is no concrete proof against him. Can you please suggest what my course of action should be in this case?