Brickie Dave Sharp hoped to trace his real family after discovering he had been given away by his mother at a train station.

But he was stunned to find his family history would make the fitting basis for a novel by his secret' real-life brother - novelist Ian McEwan.

Mr Sharp, 64, was adopted after his mother became pregnant during a wartime affair.

It was arranged following an advert in the personal column of a newspaper. Wedged between musical instruments and second-hand furniture, it simply read: "Wanted, home for baby boy, age one month: complete surrender."

The infant was given to Rose Sharp and Mr Sharp grew up in south Oxfordshire, unaware he was adopted until he was 14.

The matter remained closed until eight years later, after his adoptive mother died, but all his father Percy would say was that they had got him out of a newspaper.

After Percy died, Mr Sharp found the advert, but did not pursue the matter until he was 60.

He said: "I was about to get married (when I traced the advert), buy a new house and get a mortgage, so I put it all on the back-burner for a while."

But the not knowing ate away at him, so he wrote to the Salvation Army's Family Tracing Service.

A month later, he was told his half-brothers and half-sister had been found.

When contacted, they said they had no knowledge of another brother being adopted.

Their mother had Alzheimer's disease, so could not answer any questions. They contacted their half-brother - Ian McEwan - who also knew nothing.

But talking to their aunt, she admitted their mother - also called Rose - did give away a child at Reading railway station.

Mr Sharp said: "My mother swore her to secrecy on the way home on the train and she never breathed a word.

"She felt very guilty for telling me and betraying the trust, but also for conspiring against me."

Bit by bit, the wartime events became clear: while her husband was away at war, Rose Wort had an affair with a fellow Army officer named David McEwan, resulting in the birth nine months later of Stuart, whose name was changed by the Sharps to David.

But when news came of her husband returning on leave, Rose put a rushed advert in the Reading Mercury and gave her son away to the Sharps.

But after her husband was killed in the Normandy landings, she was able to marry David McEwan and, six years after Dave's birth, the couple had Ian.

Ian was privately educated, went on to university and is a literary phenomenon, with his books being showered with prizes and being turned into movies.

But Mr Sharp was unaware his brother was famous until he met him and kept being interrupted by autograph hunters.

He said: "I had never heard of him. Of course, I've read all his books now, but whether he's a road-sweeper or an author is immaterial. He's just my brother to me."

Ironically, while Mr Sharp was living in Wallingford with his wife and daughter, his author brother lived just a few miles away in Park Town, Oxford, for 20 years.

Mr Sharp has also met his half-brother and half-sister, and met his mother before she died in 2003.

He has now written the whole story, called Complete Surrender, to celebrate being reunited with his biological family.

But why didn't Ian McEwan use the plot himself?

"I did suggest it," Dave laughed, "but he said it was my story and that therefore I should tell it."