Barnaby Joyce has faced more than six dozen questions about his use of parliamentary entitlements.
The former deputy prime minister has answered 79 questions put to him by an expenses watchdog over suggestions he may have used taxpayer money on trips with his former-staffer-turned-partner Vikki Campion.
Ms Campion, who gave birth to the couple's son last month, has responded to 57, the ABC reports.
The official audit of expenses by the Independent Parliamentary Expenses Authority began on February 7, the day photos of a pregnant Ms Campion were published.
Investigations are continuing and both Mr Joyce and Ms Campion deny any wrongdoing.