Superstar pianist Sir Elton John and his partner David Furnish, who has already fathered a surrogate child for the pair, are expecting their second baby together in 2013 from the same surrogate mother.

John, 65, and Furnish, 50, are reportedly expecting a sibling for their son Zachary in 2013. According to the Sun, the surrogate mother – whose identity is being kept secret – is already "several months" pregnant and is due to deliver the baby early next year. This is reportedly the same woman who gave birth to the couple’s first child Zachary, who will turn 2 in December.

"Elton and David love this lady like a sister and they feel indebted to her for life,” The Sun quoted a source close to the couple as saying. "Naturally she has been well rewarded. But her identity will never be revealed."

The civil partners, who have been married since 2005, have frequently spoken of their desire to have more children.

Last summer, Sir Elton said, "I'd love to have more children. I want to have a brother or a sister to go to school with [Zachary] so that he can have someone to play with."

Both partners understand the difficulties their children might face being raised without a female parent. In an interview with NBC, Sir Elton said, "It's going to be heartbreaking for him to grow up and realize he hasn't got a mummy. But he's so happy. I've never seen a more contented child. And you have never seen two more contented people as David and I."

John, who is currently on tour in Australia, has not yet commented on the report.

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