Gordon Brown was "in tears" when his son's medical records were published in The Sun, the former Prime Minister said this morning.
Mr Brown has spoken out about claims News International targeted his personal information, and accessed private information about his child, who has cystic fibrosis.
News International denied that any medical records were accessed, and said in a statement later on Tuesday that the story was provided by a member of the public.
He told the BBC: "They told me they had this story about Fraser's medical condition and that they were going to run this story."
Asked how it affected him as a father, he replied: "In tears. Your son is now going to be broadcast across the media. Sarah and I were incredibly upset about it, we're thinking about his long-term future, we're thinking about our family. But there's nothing that you can do about it. You're in public life and this story appears, you don't know how it's appeared.
"I've not questioned how it appeared. I've not made any allegations about how it appeared. I've not made any claims of how it appeared but the fact is it did appear, and it did appear in the Sun newspaper."
Mr Brown was reluctant to discuss his private life, saying: "I have never, never talked about my son or wanted to talk about my two sons or my late daughter in public. I have always very reluctant to bring them into the political arena. I have never thought it was right that the private lives of young children who are growing up, who might want to have an ordinary life should be paraded across the media.
"I have always sought to keep them from the glare of publicity. And I think the record will show that that is exactly what I did at Downing Street. Despite people wanting to have all sorts of stories about their private life and the family's private life.
"So, I've never talked about my son's medical condition before, I've never talked publicly about my son's medical condition...
"I've never talked about it I'm not sure that even at this stage I want my son to be able to go on the internet when he's six or seven and find all these stories that have been written about him. I think the invasion of privacy of young people, young children, is a big issue."
He continued: "I've never talked publicly about Fraser's condition. And obviously we wanted that to be kept private. For all the obvious reasons as a parent you want to do the best by your children. I've never complained about what happened to me before. But the truth is that information did come out. I was approached by the Sun newspaper, who told me they had this story about Fraser's medical condition and that they were going to run this story."
Mr Brown confirmed Rebekah Brooks had phoned him to discuss the story.
"The problem that I have is, if this is a policy of newspapers in this country that they're going to write about the medical conditions of young children, then you have got to ask yourselves: where have they got this information from?"
In a wide-ranging interview, the former Prime Minister spoke out about the Sunday Times accessing his private files and condemned News International for intruding on people's private grief. He also alleged the company had links to criminality.
"I think what happened pretty early on in government is that the Sunday Times appear to have got access to my building society account, they got access to my legal files. There's some question mark about what happened to other documentation, tax and everything else.
"But I'm shocked, I'm genuinely shocked to find that this happened because of their links with criminals, known criminals who were undertaking this activity, hired by investigators who were working with the Sunday Times. And I just can't understand this. If I, with all the protection and all the defences and all the security a Chancellor of the Exchequer or Prime Minister has is so vulnerable to unscrupulous tactics, unlawful tactics, to methods that have been used in the way that we found, what about the ordinary citizen?
"What about the person like the family of Milly Dowler who were in the most desperate of circumstances, at the most difficult occasions in their lives, in huge grief and trouble, not knowing where to turn. And then they find, as they have found in the last few days that they are totally defenceless at this moment of greatest grief from people who are employing these ruthless tactics, with links to known criminals."
He said he believed News International had links to the criminal underworld.
"I believe now from what I've seen and heard and what has been told to me by people who've investigated this, and I'm looking at the evidence that's been accumulated by Nick Davies of the Guardian...
"That the links that made possible the intrusion into people's lives, particularly the intrusion into the lives of completely innocent citizens who deserve to have their privacy in their lives, particularly at times of greatest grief - at the times when they're at their most vulnerable, that News International were using people who were known criminals. People who had, in some cases criminal records, and that News International as a result were working through links that they had with the criminal underworld.
"And I think when people find out that the invasion of their liberties, their private lives and their private grief, and their private thoughts and their innermost feelings becoming public property as a result not of a rogue reporter, or a chance investigator or someone saying something out of turn when they meet a friend on a street corner...
"But because criminals were hired to do this particular work and these were known criminals.
"These were criminals in some cases with records, in some cases with records of violence. And these links have now got to be explored. And I find it quite incredible that a supposedly reputable organisation made its money, produced its commercial results at the expense of ordinary people by using known criminals. And that is now what has got to be investigated."
Mr Brown denied he had ever a "good relationship" with News International, saying that the Sunday Times had "blagged" private information.
"I complained at the time to the building society. I complained at the time through my lawyers to the Sunday Times. I wanted an apology about what happened. But I did not know at this time...
"That they had hired criminal elements to do this. I did not know at this time about their links with the criminal fraternity. I only found out as a result of the investigations that had been done...
"I've only found out the links between the Sunday Times and what I would call elements of the criminal underworld who were being paid, while known criminals, to do work that was, if you like the most disgusting of work. Not against me only but against people who were completely defenceless."
He said he believed there was an exploitation culture "in both the Sunday Times and in other newspapers in News International".
"I'm talking about people who were at rock bottom. Rock bottom was the rock upon which the Sunday Times founded their reputation and other newspapers in News International founded their reputation for purely commercial gain and in some cases to abuse political power."
Mr Brown alleged News International dropped their support for the Labour party in the 2010 election because they "stood up" to the company.
"I think when the record of my time as prime minister is looked at, and all the papers will be there for people to see, they will show that we stood up to News International. That we refused to support their commercial ambitions when we thought they were against the public interest. That we did not allow them to take decisions, allow them to pursue actions which were purely in their commercial interest but against the public interest.
"I think people will find it is partly because we stood up to News International and partly because we refused to go along with some of their commercial proposals that were purely in the interests in their company that News International did not find that they could support the Labour party at the last election."
Mr Brown claimed that News International had "an agenda about the BBC. They had an agenda to neuter Ofcom, the regulatory organisation and they had an agenda also in relation to the pursuit of their own commercial interests."
In a damning statement, he claimed: "The fact of the matter is that I had my bank accounts broken into, I had my lawyer's files effectively blagged as they call it, the Sun were getting information from my lawyers. My tax returns went missing at one point. Medical records have been broken into. I don't know how all this happened but I do know one thing: That in two of these instances there is absolute proof that News International was involved in hiring people to get this information. And I do know also that the people that they work with, because this is what really concerns me most are criminals, known criminals."
He said government had a "duty" to "clean this up" adding that his efforts to secure an inquiry had been blocked: "I tried in government to do the best I could to have a totally clean relationship with these newspapers.. Equally, at the same time, I tried to secure a judicial inquiry."