Are there any bodies that regulate the behaviour of members of parliament?

Yes, the National Anti-Corruption Commission is an independent agency that investigates and reports on serious or systemic corruption in the Australian public sector. This includes the behaviour of members of the Australian Parliament.

There are many other ways that members are held accountable for their actions and in which their behaviour is regulated:

• Like all Australians, members of Parliament must obey the law and can be held accountable by the legal system if they break the law. If a member of Parliament has been found guilty of a serious crime or is an undisclosed bankrupt they can be disqualified from sitting in Parliament under section 44 of the Australian Constitution.
• In the Senate and House of Representatives the Standing Orders define disorderly behaviour and how it will be dealt with during meetings in Parliament.
• The Prime Minister and ministers are held to account in the Parliament. Any member of parliament can examine the work of ministers and the government in Question Time. Ministers may also be required to attend Senate estimates hearings to explain the work of the government department they are responsible for.
• Each government also sets its own statement of ministerial standards. This Code of Conduct is not a law or regulation. It is controlled by the Prime Minister, not the Parliament.
• The media has an important role in scrutinising – closely examining – the work and behaviour of members of Parliament. 
• Citizens also play an important role in keeping members accountable by voting in elections.