There is often confusion regarding the nature of the National Security and Intelligence Committee of Parliamentarians. It is not a parliamentary committee, properly speaking.
Although its name suggests that it is, it is not a parliamentary committee; it is actually a statutory committee that was created by the National Security and Intelligence Committee of Parliamentarians Act. Yes, it is composed of parliamentarians, but it operates within a framework that is not parliamentary. In fact, the parliamentarians who sit on the NSICOP have to get the appropriate clearance. There is also an express exception in the act regarding parliamentary privilege, which means that members who receive information classified as secret in the course of their work on the NSICOP could not then disclose the information in the House of Commons, since there is a provision stating that parliamentary privilege cannot protect them in that case.