Relationship between immunities and powers
The immunities of the Houses and their members and the powers of the Houses, particularly the power to punish contempts, although referred to together by the term "parliamentary privilege", are quite distinct. The power of the Houses in respect of contempts is a power to deal with acts which are regarded by the Houses as offences against the Houses. That power is not an offshoot of the immunities which are commonly called privileges, nor is it now the primary purpose of that power to protect those immunities, which are expected to be protected by the courts in the processes of the ordinary law.
In the past, references to contempts as "breaches of privilege" led to the erroneous notion that each contempt is a violation of an immunity. Obvious offences against the Parliament were referred to as if they were violations of particular immunities, and immunities were distorted, or new supposed immunities were invented, to correspond to each contempt. Thus intimidation of witnesses was supposed to be a violation of freedom of speech, and assaults upon members were supposed to violate what was called the privilege of freedom from molestation. There was some doubt about treating obvious offences against the Parliament as contempts because the particular immunity which they violated was not readily apparent. For example, the unauthorised publication of in camera evidence is clearly an offence, but which particular immunity does it violate?
Similarly, it is sometimes said that because the Houses of the British Parliament resolved in the 18th century that reporting of their proceedings was a breach of privilege (i.e. a contempt), and because those resolutions were not rescinded until after 1901, it must technically be an offence for anyone to report the proceedings of the Houses of the Australian Parliament. This misconception also stems from the confusion between immunities and powers. Section 49 of the Constitution confers upon the Houses of the Australian Parliament power to declare acts to be offences and to punish those acts; it does not mean that acts which have been declared to be contempts in the United Kingdom are automatically contempts in Australia. Since the Australian Houses have not declared reporting of their proceedings to be a contempt, the resolutions of the British Houses are of no consequence, and the problem simply does not arise in Australia.
This confusion between immunities and powers is still so deeply entrenched in much discussion of parliamentary immunities and powers that it is very difficult to avoid it. The matter is discussed more fully in the 1967 House of Commons report, in the Senate submission to the 1984 joint committee, and in various advices to, and reports by, the Senate Privileges Committee.