Under the design and mobilisation contract, signed on 30 September 2016, Defence and Naval Group were required to produce the Australian Industry Capability Plan and an Australian Steel Development and Qualification plan within five months of the contract signing.
Members of the Nick Xenophon Team (NXT) have been pursuing the documents since last year, with former senator Nick Xenophon grilling Defence at the October Senate estimates.
Rear Admiral Greg Sammut, Head of the Future Submarine Program, said that while Defence was previously on schedule in meeting all milestones for the design and mobilisation contract, the relevant parties fell behind in August last year.
"We're still working on the Australian Industry Capability Plan with Naval Group, and similarly with the study for the Australian development of the steel and so forth," RADM Sammut said.
"There have been some delays with the work that we want to do with Australian industry on the steel study."
RADM Sammut said the hold-up related to Australian steel companies implementing "appropriate security arrangements."
"It took longer than we expected to put in place the security arrangements with Bisalloy and BlueScope, who will be responding to the request for information that will form an important part of that study," he said.
Deputy Secretary of Defence's Capability Acquisition Group (CASG) Kim Gillis stressed the reasons for delay related to security.
"I think it's important to note that the delay's because we were ensuring that we got the appropriate security classification, that companies in Australia had met the requirements," Gillis said.
"I think it's just good process to ensure that we're doing the right things and following the process. It's very early on in the process. We've got to make sure that we do it diligently."
Defence maintains that while the plans are overdue, it will not affect the delivery of the Future Submarine Project.
"There's no need to order steel now," RADM Sammut told Senate estimates.
"The steel specifications for the submarine are set – that is, the steel specifications to which the submarine will be designed. The source of supply will need to be determined in time to support the build of the Future Submarine, which will not be commencing until the early 2020s."
RADM Sammut said the department hopes to have the Steel Development and Qualification Plan delivered early this year, however, the overall strategy for the Australian Industry Capability Plan will take longer.
"In terms of having the product that we want at this stage, there has been a slight delay," RADM Sammut said.
"What we are realising is that, as we get further into the design phase, we need to develop that plan to a greater level of detail to support all the work that will be done during design and the work that will lead into construction."
Defence Connect contacted the Department of Defence for further comment and updates on both documents, but none were provided at the time of publication. Naval Group also declined to comment.