A submission on the capital gains tax was presented to the federal cabinet in late 2016 or early 2017.
A freedom of information request lodged by AAP has been rejected despite Treasury identifying 18 documents that related to "correspondence, meeting notes or reports of modelling produced by Treasury in relation to potential changes to capital gains tax".
In rejecting the FOI request, senior Treasury official Robert Ewing said he had identified a "cabinet submission that was submitted to cabinet after being created for the dominant purpose of submission to cabinet".
He also identified a "brief to a minister on a cabinet submission that was presented to cabinet".
In February, Prime Minister Malcolm Turnbull declined to answer a Labor question in parliament about whether he had personally sought advice or modelling on the issue.
News that makes sense
Your trusted source for staying up-to-date with the world around you. Get free daily news updates and analysis, straight to your inbox.
However, he said the government was "paying very close attention to the damage that would be caused by the capital gains tax proposals of the Labor Party".
Labor says reforming capital gains tax concessions, as well as overhauling negative gearing, is key to making housing more affordable.
Treasurer Scott Morrison is expected to announce a housing affordability package in the May budget.
Earlier this week he described Labor's housing plan as "dangerous and dramatic ... with no thought or appreciation of the consequences".
