Mobile carriers are to be forced to reveal wholesale and retail margins on trans-Tasman voice and data roaming services.
The Australian Competition and Consumer Commission (ACCC) is to be given $1.3 million over four years to investigate the way such services are charged for by telcos.
"The ACCC will publish an annual roaming pricing report to increase price and margins transparency for trans-Tasman roaming," the Government said in Budget 2013-14 statements.
The full $1.3 million cost is to be recouped from the annual carrier license charges paid by telcos to the Australian Communications and Media Authority (ACMA).
The Government did not mention whether or not those carrier fees would need to rise to accommodate the roaming investigation and transparency reports.
The investigation comes as the Government moves to introduce legislation aimed at bringing down trans-Tasman roaming rates by the end of parliament's winter sitting.
The legislation would allow roaming services to be regulated "where reciprocal arrangements apply with another country".
The Australian and New Zealand Governments have been jointly proposing to break the high costs of roaming between the two countries since February 2012.