Captain Lawrence "Titus" Oates is best-known known for telling his companions "I am just going outside and may be some time" before he disappeared as the 1912 expedition came to a tragic end.
A new biography claims Oates had a sexual encounter with Henrietta Learmont McKendrick, who was known as Etta, from Johnstone, Renfrewshire, in 1899.
The book says that Oates never knew he had a daughter.
Frost-bitten feet
Captain Robert Falcon Scott, Oates and three other explorers died on their return from the South Pole in 1912.
They had been beaten in their race to the pole by a Norwegian party led by Roald Amundsen.
Due to badly frost-bitten feet, Oates began to find it impossible to keep up with his companions.
He walked to his death in a blizzard, feeling the others would have a better chance of reaching the next depot without him.
It is thought that he never knew he was a father.
Strictest privacy
The book, I Am Just Going Outside by Michael Smith, claims that Etta's mother was so shocked by the scandal of the youngster's pregnancy that she took her to a secret location in Ireland to have the child in strictest privacy.
The date of the little girl's birth is given as 24 March, 1900.
Etta was born in October 1887, which means she was a few months short of her 12th birthday when Oates slept with her and only 12 and a half when the child was born.
Oates was 20 when the child was born.
The child, Kathleen Gray, was brought up a London sanctuary and formally adopted by one of the nurses, Blanche Wright.
As a child, Kathleen was told that both her parents were dead.
Famous ancestor
But Blanche knew the truth and in the 1920s, she finally disclosed that Kathleen's father was the famous Captain Oates.
Kathleen married in 1926 and raised two children. But only towards the end of her life did she reveal the truth to her own children.
The Oates family refused to speak about a biography of their famous ancestor.
Oates has always been regarded as a hero and won a recommendation for the Victoria Cross during the Boer War.