Voters are suspicious because the talks are taking place in extreme secrecy.

In both cases the speakers emphasized extreme secrecy of the matter.

Construction was in full swing (but in extreme secrecy, to avoid getting scooped by competitors) by early 2009.

Project-706 led to the creation of multiple production and research sites that operated in extreme secrecy and ambiguity.

The flight tests were carried out in extreme secrecy, taking off and landing under propeller power, and only flying in the early morning before other workers had arrived.