The current setup for my team is a team of developers that report to a manager (who is part of the company management), we take calls directly from the client and these calls happen very frequently and this leads to bonding between the company employee's and the company client. Our team client is only a single person who handles multiple projects and assigns work to us.
One of my senior team members left our company after almost 4 years of service and started working for the company client directly, while the company policy clearly states that we cannot work for any of company's client's after leaving upto 2 years. (roughly, that's what it says). My other senior team members ask me to hide this from the management/other employees as it may put our team in trouble (we won't be allowed to leave easily as it raises the same doubt on us).
I'm a junior member of the team and I don't like this unethical behavior of my senior. Do I need to let the company management know about this as this in the future may lead to loss of business for the company that I work for? How do I approach the management/client/employee? Looking for advice on ethical approaches which does not put anyone in trouble as we all make mistakes. Thank you