Fortescue Metals Group said that Brockman should not be allowed to access its railway under third party access laws.

The company accused Brockman Mining of lacking the capacity of exporting its produce along the railway. The company is aiming to protect its strategic position in the Pilbara iron ore industry and said that it does not have spare capacity to share it with the other firm. The company said that it is expanding its railway to carry 155 million tonnes of ore a year and it is expected to be completed during the second half of 2013 as it needs more capacity to carry iron ore to the shores for export.

"As Fortescue is utilising all the capacity of TPI's railway, unless there is further expansion beyond Fortescue's planned expansions, there is no capacity available to Brockman," Fortescue wrote in a filing with the submission to Western Australia State Economic Regulatory Authority. The Pilbara Infrastructure, or TPI, is the wholly-owned rail and port division of Fortescue.

Brockman, which is expecting its project to mine 20 million tonnes of ore a year, is facing transportation issues for its produce. The company is eagerly trying to gain access to Fortescue's 220 km railway line that runs across the western outback to Port Hedland on the Indian Ocean. It is also considering other options like building its own railway with commercial rail operator Aurizon Holdings in association with Flinders Mining.