Gordon Brown has denied he volunteered permission for The Sun to publish a story on its front page saying his child had cystic fibrosis.
The intervention from the former prime minister and his wife, Sarah Brown, came after former News International boss Rebekah Brooks said the prime minister had given permission for the story to be published.
"They felt that, as prime minister, there were an awful lot of parents coping with cystic fibrosis and one of the overwhelming memories is that when the story was published they wanted us to highlight the positives," Brooks told the Leveson inquiry into media standards.
But on Friday evening Gordon and Sarah Brown said it was "untrue" that they had given permission for the story to be published.
"The idea that we would have volunteered our permission or were happy that a story about our son's health was about to enter the public domain is untrue..
"We remain concerned that there is no satisfactory explanation of how private medical information, known to very few people, got into the hands of The Sun and the possible payments involved."