Radio 4 presenter Justin Webb has revealed for the first time he is the secret son of respected newsreader Peter Woods.
The Today programme host, 50, had no contact with his late father apart from a brief encounter at the age of six months and has kept his identity under wraps throughout his life.
Woods was a celebrated host of the BBC's flagship Nine O'Clock News and one of the great characters of his day.
Famously, one BBC2 bulletin in the 1970s had to be faded out when he was audibly slurring his words.
Webb has gone public about his father by writing about him for the first time in the new edition of Radio Times.
Webb said he "buried" his father's identity in his mind to the extent he felt little connection and never considered getting in touch, even when he followed in the same career.
But he said he decided to go public rather than being forced to respond to the news getting out in other ways.
"If Peter Woods had been a private individual, a name and occupation and a few photos would have been enough. But he was not a private individual - he was once famous.
"So although I'm a relatively obscure BBC person I know that the link will be of some perfectly legitimate interest to those who remember my father. And rather than read about us in a gossip column one morning, or have to respond quickly to something that someone else was writing after trawling Facebook, I decided to write this."
Woods and Webb's mother Gloria Crocombe became close while working together at the Daily Mirror in the late 1950s - he as a star reporter and she as a secretary, until she was sacked for becoming pregnant.
They split when Webb was born in 1961 and the presenter - who spent many years as the BBC's north American editor until his appointment as one of the Today hosts - believes his mother may have had as much to do with the separation as his father.
"I do not believe she was abandoned," he said. "But the plain fact is that, emotionally and physically, he was absent.
"He had a life and a family of which I was no part."
Webb said he would see his father on TV while he was growing up but did "not really make much of a connection between him and me".
He wrote: "I acknowledge this is odd, but there it is. My mother had taken a decision to be reticent and children are nothing if not adaptable. Reticence was for Mum and reticence was for me.
"I cannot even remember wanting to tell anyone, it was that deeply buried. And when I left university and wanted to join the BBC, I applied for a traineeship.
"He was by then retired but very much alive, and I can honestly say that I never thought of making contact. I built my career without consciously aping his; without giving him much of a thought.
"Peter Woods was a presence in my life - and a lack of presence all wrapped up in one."
Webb - also a former host of BBC1's Breakfast News for several years - said it would have been "inconceivable" to make contact with the well-spoken but crumpled-looking Woods while his mother was alive.
"Why? It's the same reason Michael Gove, the Education Secretary, gives when you ask him why he doesn't try to find his mother, who gave him up for adoption when he was young - it's the fear that those who do care for you will be given the message (even if it's untrue) that in spite of that care something has always been missing."
Although he bears no ill-feeling towards his parents for the paths they chose, he admitted: "I do sometimes feel a pang of longing."
"I think sometimes that it would have been fun to have had a proper dad, less intense and less lonesome. More normal, in the best sense. It has left me fascinated by fatherhood: its possibilities and limitations and joys," he added.
Webb - whose mother died in 2006 - said he had hoped to keep his father's identity secret forever but realised it was "naive".
He said he needed his children to be able to know who their grandfather was and be able to talk to their friends - "several of whose parents are very chatty members of the chattering classes".
Although Webb's mother later married, he said the union was not happy. The broadcaster, who went on to be educated at a Quaker boarding school, said: "My life was rescued by my mother's unswerving love."
Unwittingly, a number of people have struck up conversations with Webb
about Woods, including former Labour leader Neil Kinnock, but he kept his silence.
And he said: "I still think of him as Peter Woods first and my father only after some thought."
Woods made headlines in 1976 when he went on air, apparently drunk, and struggled with his script as he read a bulletin during BBC2's Newsday programme. Main presenter Robin Day had to explain to viewers, after Woods was faded out: "We leave the newsroom earlier than expected."
At the time the BBC put the incident down to the newsreader using medication for "sinus problems". However he continued as a newsreader, including a stint on the prestigious BBC1 Nine O'Clock News.
Webb joins a number of other public figures who have been involved in revelations about parentage.
The late TV presenter Paula Yates learned in 1997 she was the daughter of Opportunity Knocks host Hughie Green, after spending her life believing Stars On Sunday broadcaster Jess Yates was her biological father. She died of a heroin overdose three years later.
In 1996 the then MP Clare Short - later to become a Labour cabinet minister - was reunited with the son she had put up for adoption while
she was a teenager.
And in 1999, a DNA test showed that former Tory minister Jonathan Aitken was the biological father of Petrina Khashoggi, rather than billionaire arms dealer Adnan Khashoggi.
Webb's Today programme co-host John Humphrys - a former colleague of Woods - told Radio Times that he assumed that Webb was "winding me up" when he called him to let him know about his father.
"It's true that the dates worked - Justin is 50, so Peter would have been 30 when he was born - but everything else seemed improbable," he
"Apart from anything else how can father and son be quite so different?"
Humphrys said the drinking culture of journalism during Woods's era contributed to his downfall.
He said: "What this strange and sad story illustrates is not so much how people change, but how times change. Both Peter and Justin are the products of their generation.
"Peter cut his journalistic teeth in the days when the stereotype was the misogynistic, hard-drinking, expenses-fiddling, risk-taking, devil-may-care, cynical old hack."
He added: "By the time Justin joined the BBC, that era had pretty much ended."
* The new issue of Radio Times, containing the full accounts by Justin Webb and John Humphrys, is on sale from today.