An adopted brick-layer who traced back his family history discovered his brother was the internationally celebrated author Ian McEwan.
Ian McEwan is an internationally popular author
Dave Sharp from Oxfordshire was given away at Reading station by his mother, Rose McEwan, nee Wort.
She became pregnant from a wartime affair with David McEwan, and gave the child away before her husband returned.
When he was killed, Rose married Mr McEwan, and they raised Ian only 15 miles from Mr Sharp's new home.
The novelist was born six years after Mr Sharp, but both men grew up without knowing of the other's existence.
Mrs McEwan had put an advertisement in the local paper and her baby was handed to Rose and Percy Sharp at the railway station.
Mr Sharp, now 64 and living in Wallingford, went on to work in the building industry.
Mr McEwan CBE, 58, attended a private school, then a university and later achieved international acclaim for novels such as Atonement, The Cement Garden and Enduring Love.
Mr Sharp, with the help of the Salvation Army's Family Tracing Service, traced Mrs McEwan's children with her first husband before finding his brother Ian.
He told BBC News: "I'd been told by the Salvation Army that they'd got people together in the past who'd wound up fighting, but I just wanted to know."
Mrs McEwan developed Alzheimer's disease and died in 2003.
Mr Sharp said his brother's fame only became apparent to him when autograph hunters interrupted their first meeting in a pub.
Mr Sharp added: "I'd no idea who he was and to be honest it didn't matter what he did - I'd just wanted to find any other family."
Mr Sharp is now writing a book, Complete Surrender, about his experiences, aided by ghost-writer John Parker.