A taskforce investigating allegations of sexual and other abuse in the defence force is receiving so many complaints it's been given an extra six months to complete its work.

New complaints to the taskforce's hotline had been building steadily since it opened last November, Defence Minister Stephen Smith told federal parliament on Thursday.

"In addition to the more than 1000 DLA Piper cases, the taskforce is receiving approximately 15 new matters per week through the hotline," the minister said.

At March 4, there had been 1041 complaints.

Some 781 were made by phone call and voicemail messages while 260 were sent by email.

There were 328 fresh claims of abuse.

Taskforce chairman, retired judge Len Roberts-Smith, told Mr Smith there was no realistic prospect of its work being completed within the initial 12-month term.

So the government has agreed to agreed to a six-month extension, with the taskforce now due to conclude its investigations by the end of May 2014.

As well, there will be an end-of-May 2013 deadline for new allegations to be made.

Law firm DLA Piper was commissioned to examine a number of allegations of abuse in the Australian Defence Force, following the Skype scandal at the Australian Defence Force Academy (ADFA) in 2011.

The firm uncovered 775 plausible abuse allegations across every decade since the 1950s. The earliest related to events in 1951.

The Defence Abuse Response Taskforce is examining individual allegations, which if sufficiently substantiated could allow victims to claim up to $50,000 in compensation.

It is also considering whether a full royal commission is needed to address outstanding allegations at ADFA in the 1990s and allegations of sexual and other abuse of naval cadets at the former navy training centre, HMAS Leeuwin, which operated from 1960-84.

The taskforce said it appeared the abuse at Leeuwin occurred in the 1960s and 1970s.

"Much of the alleged bullying and violence appears to have been unreported," Mr Smith said.

Opposition defence personnel spokesman Stuart Robert said the coalition fully backed the inquiry.

"We are satisfied that the processes and procedures that have been put in place are appropriate and are working to the fullest extent possible," he said.