The baby scandal involving the former deputy prime minister caused him to lose his Cabinet position and Nationals leadership.
At the time, the newspaper said the pair was expecting a child together and its reporter Sharri Markson insisted she put the question of whether Mr Joyce was the father directly to his office before her story was published.
'I would say Barnaby is pretty angry in every direction, particularly with the National Party, ' she told Sunrise.
Hours after the story was published, Mr Joyce released a statement saying he and Ms Campion felt they had "no choice but to tell the story" given media requests and continued paparazzi attention.
Joyce, 50, maintains he will look after the child regardless.
The Age earlier reported that Mr Joyce's travel schedule could indeed throw doubt over the paternity of the baby.
At the same time Ms Campion was in far north Queensland. He told reporters on Monday at a press conference that anything that is personal in nature is a business between only him and partner Vikki Campion.
It has been a tumultuous month for the new couple, with news of their relationship splashed across front pages around the country and sparking a feud with Prime Minister Malcolm Turnbull, who responded with a ban on sexual relations between ministers and their staff.
Ms Campion, with whom he now lives, was present for part of the interview and heard his answers.
Mt Joyce has expressed concern that the new baby boy would be subject to unfair scrutiny throughout his life, thanks to the circumstances surrounding his conception and upcoming birth.