Labour MP Stephen Pound has told of his shock and his joy on learning he fathered a daughter when he was "out of control" during the "wild" 1960s.
Mr Pound is now is regular contact with his daughter
Lucy, 36, tracked down Mr Pound after her birth mother told her he was known as "Precious" at school.
Despite being told he was a "nutter who died at sea" she found a reference to Mr Pound on Friends Reunited.
Lucy's mother kept her pregnancy secret and had her adopted at four weeks. Mr Pound found out about it last year.
That happened when Lucy wrote to his Parliamentary office saying she believed he was her father.
Mr Pound, who is now married with two other teenage children, said: "I was a nutter and I was a sailor but I wasn't dead."
He said his first reaction was to wonder if he was victim of a "set-up" but he then realised all the dates fitted.
"It was a pretty horrible thing with a pretty happy ending. I felt guilt in the marrow of my bones," said the Ealing North MP.
"I don't blame Lucy's mother. I was pretty much out of control. I was 18 when she was conceived. It was a different time - it was pretty wild."
Mr Pound says he rang Lucy as soon as he got her letter, they met up and have been in contact ever since.
Describing that first meeting at London's King Cross station, he said: "The earth went from under my feet ... We were walking across the Euston Road and I took her arm to take her across and there was an immediate connection.
"We were finishing each other sentences."
Lucy, who was adopted by a family from Essex, wants to remain anonymous for the sake of her adoptive father and her children.
Mr Pound said his wife Maggie had been fully supportive and their two children Emily, 16, and Pelham, 14 were pleased to have an older sister.