Tilda Swinton's former beau was born out of incestLondon, March 19 (AZINS) John Byrne, former boyfriend of actress Tilda Swinton, says he was born after an incestuous relationship between his mother and his grandfather.

Artist and writer Byrne revealed in an interview with The Times UK that he was told the truth about his parents by his cousin in 2002 at the Scotland home he shared with Swinton, reports nydailynews.com.

His cousin Aileen was told the news by her mother before she passed away and she then confided in Swinton who said Byrne deserved to know.

"Do you think I should tell Iain (a family name for Byrne)?" Aileen had asked Swinton.

To that, she replied: "You've got to tell him."

"She called me in and handed me the phone," Byrne said.

His mother never told him of the relationship and passed away in the 1980s. She suffered from a mental illness, which Byrne believed was a result of being "utterly and totally" in love with her own father.

"I think he gave me that wonderful mixture of genes with his own daughter, the eldest of the family. That's what they do in Ireland," he said, adding that "I presume it's what they do in unlettered places and lettered places. It's traditional, and nobody speaks about it".

Byrne and Swinton, 56, split in 2005 and he has since been dating lighting designer Jeanine Davies.