A radical reorganisation of national security agencies, such as the creation of a US-style Department of Homeland Security, is not necessary because existing arrangements are working well, experts and former officials say.

Fairfax Media has confirmed with government sources that two of Australia's major security agencies, the Australian Federal Police and ASIO, have told senior members of the Turnbull government they do not support such an amalgamation.

A majority of the permanent members of the powerful National Security Committee of cabinet are also understood to oppose the move, including Foreign Minister Julie Bishop, Defence Minister Marise Payne and Attorney-General George Brandis.

Ms Bishop and Senator Brandis spoke publicly against the idea when it was raised in 2014 under the then-prime minister Tony Abbott, and it is understood their positions have not changed. The ministers' offices were contacted for comment.