But he insisted he was not disturbed by it.
"In the last month I have discovered that my biological father is not Gavin Welby but, in fact, the late Sir Anthony Montague Browne. This comes as a complete surprise," Welby said in a highly unusual statement issued through the Church of England.
"I know that I find who I am in Jesus Christ, not in genetics, and my identity in him never changes."
Welby had assumed that his father was Gavin Welby, a whisky salesman who died in 1977.
But the Telegraph said it had found evidence suggesting that Montague Browne was actually his father, a finding it then discussed with Welby who decided to take a DNA test.
A comparison between a swab from his mouth and hair samples from Montague Browne, who worked for Churchill between 1952 and 1965, showed a 99.9779 percent probability that they were father and son.
Welby said both his mother Jane and Gavin Welby had been alcoholics, although he stressed that his mother had not drank alcohol for nearly 50 years.
"To find that one's father is other than imagined is not unusual. To be the child of families with great difficulties in relationships, with substance abuse or other matters, is far too normal," he said in his statement.
"Although there are elements of sadness and even tragedy in my father's (Gavin Welby’s) case, this is a story of redemption and hope from a place of tumultuous difficulty and near despair in several lives."
Welby's mother Jane also issued a statement saying the news had come as an "almost unbelievable shock".
She confirmed she had slept with Montague Browne shortly before marrying Welby, "fuelled by a large amount of alcohol on both sides".
Montague Browne died in 2013.
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"In the last month I have discovered that my biological father is not Gavin Welby but, in fact, the late Sir Anthony Montague Browne. This comes as a complete surprise," Welby said in a highly unusual statement issued through the Church of England.
"I know that I find who I am in Jesus Christ, not in genetics, and my identity in him never changes."
Welby had assumed that his father was Gavin Welby, a whisky salesman who died in 1977.
But the Telegraph said it had found evidence suggesting that Montague Browne was actually his father, a finding it then discussed with Welby who decided to take a DNA test.
A comparison between a swab from his mouth and hair samples from Montague Browne, who worked for Churchill between 1952 and 1965, showed a 99.9779 percent probability that they were father and son.
Welby said both his mother Jane and Gavin Welby had been alcoholics, although he stressed that his mother had not drank alcohol for nearly 50 years.
"To find that one's father is other than imagined is not unusual. To be the child of families with great difficulties in relationships, with substance abuse or other matters, is far too normal," he said in his statement.
"Although there are elements of sadness and even tragedy in my father's (Gavin Welby’s) case, this is a story of redemption and hope from a place of tumultuous difficulty and near despair in several lives."
Welby's mother Jane also issued a statement saying the news had come as an "almost unbelievable shock".
She confirmed she had slept with Montague Browne shortly before marrying Welby, "fuelled by a large amount of alcohol on both sides".
Montague Browne died in 2013.
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