I do recall observing something similar number of years ago. The issue was the Chairman had reasonable grounds to suspect an individual within the chamber was providing/divulging information from the confidential session to one of the prospective contractors. The key been he could not prove it (merely suspected) so was not prepared to say who. I gather eventually a number of members confronted the Chair (with Vice & Clerk stood next to them) and basically said they all resented the constant insinuations either put up or shut up in effect as politely as possible.