Salient. Victoria University Student Newspaper. Vol 35 no. 10. 24 May 1972
During the teach-in on the security intelligence service Chris Wheeler gave evidence that he had discovered a telephone bug or tap at Courtney Place exchange. Chris had to rely on the services of a friend inside for his info, but in fact almost anyone can get to examine the point at which their telephone is terminated. Almost every exchange has a sign inviting inspection from members of the public or persons interested in a career in telephony. A technician in showing you how it all works usually sets up a call from your number. He will most likely do this from what he calls a uni selector, but with suitable prompting he will show you "where the wires actually come into the exchange." This is at the main distribution frame (M.D.F. in his language) which on one side has all the numbers serviced by the exchange arranged in numerical order. Given suitable encouragement the technician will show you your number. On one side of the block there should be the permanent wiring of the exchange laced against the frame with string. On the other side of the block there should be terminated one pair (i.e. one red, one white wire) unless your phone is a party line, or you have shifted recently or have two addresses.
There are of course other methods of bugging both within and without the exchange, but it seems to me that this is the method most likely used by our S.I.S. It is a very crude method, but has the advantage of needing only one bent technician. All other methods of tapping or bugging within the exchange would both require official connivance and be visible to all technical staff. Such wiring in my experience does not exist. If official connivance is ruled out all other taps or bugs must be in your phone and the pole box where the wires go underground.