Federal Parliament lacks the power to properly monitor Australia's "growing" intelligence community and the billions spent on their clandestine activities, the country's newest senator has warned.

Rex Patrick is a former submariner and defence contractor, and now sits on the Senate's crossbench with the Nick Xenophon Team.

In his maiden speech to Parliament, he has called for "enhanced accountability" for Australia's 10 national security agencies and their more than $2 billion in taxpayer funding.

"Whilst I support our intelligence services, we must also recognise that the power that comes with such an organisation must be appropriately balanced with enhanced accountability," Senator Patrick told Parliament.

The South Australian politician, who replaced his one-time boss Nick Xenophon in the Senate last month, used to advise the party on defence policy.

He believes Parliament's powerful Joint Committee on Intelligence and Security should be able to monitor operational matters, not just administrative and financial affairs.

"The Parliament, in contrast to the principles of responsible government, has carved out operational matters from its purview, but that is neither wise nor acceptable," he said.

Senator Patrick has argued that while Australia's intelligence service does, "a lot of first-class and critically important work", it could actually benefit from more scrutiny.

"Parliamentary oversight does not constrain an agency operating lawfully; rather it seeks to enhance an agency's operations," he said.

"This has long been recognised in the US where committees such as the House of Representatives Permanent Select Committee on Intelligence and the Senate Select Committee on Intelligence can delve deep into agency operations.

"This is accepted by the US intelligence community as necessary and appropriate. It should be the same here."

The NXT senator said he planned to have more to say on the, "important question of parliamentary oversight of our large and growing intelligence community".

"This should be part of a genuine push to have the Parliament and the Senate enhance its 'informing' function in relation to this vitally important but highly secret area of government," he said.