Tony Abbott has refused to answer questions on whether he leaked an early draft of the Defence Department's white paper.
As the former prime minister arrived at a dinner honouring the 20th anniversary of the election of the Howard government on Wednesday night he was asked whether he was behind the leaks.
"I'm just really delighted to be here tonight," he told reporters.
"This is a marvellous opportunity to celebrate a great government and the achievements of a really outstanding government."
Leaked sections of the paper show there were initial plans to bring new submarines into service by the mid-2020s, years earlier than the government now plans.
Commenting earlier, Mr Abbott said when he was in the top job he had intended to get the first built by 2026-27, and that he was disappointed and flabbergasted at the current plans to have them in service by the early 2030s.
Prime Minister Malcolm Turnbull told parliament on Wednesday that Defence department secretary Dennis Richardson had called in the Australian Federal Police to investigate the leaks.
The former and current Liberal Party leaders sat opposite each other at the Canberra function.
