Defence is not reviewing its contracts with BAE Systems Australia despite the firm losing a manual on the security upgrade to Parliament House.
The Defence department sought reassurances from BAE Systems Australia it can be trusted on highly classified military projects after it lost a 1000-page manual on the security upgrade to Parliament House.
The loss of the manual by BAE Systems Australia - a firm on the shortlist to win a $35 billion Navy frigates contract - was raised by Labor in a Senate committee hearing on Monday.
The major defence contractor has an estimated $2 billion of contracts with the Defence department.
Defence department deputy secretary for acquisition Kim Gillis said he spoke to the company's chief executive officer this week about the loss of the manual on a single CD.
"He gave me some context about what actually happened... how they are changing their processes," Mr Gillis told Senate estimates hearing in Canberra on Wednesday, adding he had asked for updates.
Mr Gillis said defence would not be reviewing any contracts with the company following the incident and emphasised it had occurred in a non-defence part of the company's business dealings with the Commonwealth.
"We take any loss or any security breach seriously," he said.
The manual remains missing and parliamentary officials were not told about it until three months after the event.
A BAE Systems Australia spokesperson told AAP the company understood there had been no compromise to the security of Parliament House.
"Following identification of the security incident, we conducted a thorough investigation and are confident that we have the processes and procedures in place to avoid the possibility of an incident of this nature happening in the future," the spokesperson said.
BAE Systems Australia has won a number of contracts dealing with security cameras and digital broadcasting at Parliament House.