The book, written with Hot Press' Jackie Hayden, contains remarkable new revelations about Philip Lynott's sister, Philomena Jnr., and brother Leslie, is well on the way to becoming a modern Irish publishing phenomenon, holding down the No.1 slot ( non-fiction paperback) it has made its own for the past two weeks against stiff competition from highly publicised new books, including Little Fighters – the story of the Cork-born conjoined twins Hassan and Hussein Benhaffaf – and Mary McEvoy's memoir about depression How The Light Gets In.

"It is a fantastic story, which has touched people in an extraordinary way," Hot Press editor and publisher of My Boy, Niall Stokes, said of Philomena Lynott's powerful book. "It tells a story that is tragic and painful in many respects – but it is also a wonderful human interest story of redemption, which gives a unique and profoundly encouraging insight into adoption, family and the extraordinary way in which love works."

On Saturday, Philomena Lynott will conduct a book signing in The Book Centre in Waterford, where big crowds are expected, and there are further signings planned over the coming weeks in Arklow, Kilkenny, Limerick and in further towns and cities to be announced.