THE writer and artist John Byrne has revealed that he is the child of an incestuous relationship – and that the man he thought was his grandfather was actually his father.

Byrne was brought up believing that he was the son of Patrick Byrne and Alice, formerly McShane, his mother. However, in 2002 he learned that his father was actually his 'grandfather' Patrick McShane.

At the time he was living with the actress Tilda Swinton in a house near Tain in northern Scotland. A phone call from his cousin Aileen was answered by Swinton and she was told there was news for 'Iain', Byrne's family name.

"Aileen's mother, my auntie Helen, the youngest in the McShane family had died. She told Aileen what my mother had told her when she was much younger" and Aileen asked Swinton whether Byrne should be told.

After he had been told, Byrne said, "everything fell into place". He recalled how his mother used to walk regularly the eight miles from their home in Ferguslie Park, Paisley to his grandparents' house in Cardonald.

"She was in love with her own father, utterly and totally. She just wanted to be in his company," he said.

His mother died in hospital in the 1980s after a long struggle with mental illness which, he believes, was brought on because of her relationship with McShane. One of his earliest memories was of watching from the third-floor tenement flat in Paisley as his mother, Alice, being taken away to hospital for the first time.

After a succession of confinements in hospital she was diagnosed with a form of schizophrenia and died in Dykebar Hospital aged 74.

Alice's husband Patrick went to his grave not knowing he was not the natural father of Byrne.

In the immediate aftermath of the revelation Byrne felt hatred towards the grandfather he had loved growing up. His attitude, he said, had been "he died of cancer, hell mend him". But in the years since he has reconciled himself to accepting his origins.

As a child he had never felt anything other than love for McShane and with time he could admit to himself that he had adored his grandfather.

"What did he do to me particularly that damaged me? I don't think he did damage me," Byrne said.

He went on to find fame as an artist, also known for his album covers for his Paisley musician friend, the late Gerry Rafferty, as well as Donovan and the Beatles.

Byrne also wrote the acclaimed TV series Tutti Frutti, and the follow-up Your Cheatin' Heart, where he met Swinton.