The project also involved construction of a joint venture rail line and expansion of Abbot Point port.
Guardian Australia cited sources familiar with the matter as saying that Worley Parsons and Aecon, Aurecon and SMEC were amongst the contractors pulled off with around 40 engineers working on the project.
Adani is reportedly facing legal challenges from Indigenous landholders and conservation groups on the project.
Adani spokeswoman Kate Haddan however was cited by Reuters as saying: "This is only temporary."
A statement from the company said: "For the past six to 12 months, Adani has maintained a level of investment, jobs and subcontractor engagement for its mine, rail and port projects in anticipation of finalising approvals and decisions.
"The project budget was based, understandably, on these anticipated approvals timelines and milestones.
"As a result of changes to a range of approvals over that time, it’s necessary to synchronise our budget, project timelines and spending to meet those changes."
"However, it is important to note we are now into the fifth year of development and approvals and therefore the need to finalise those approvals and timelines is critical."
