Elton John's son will undergo a paternity test

London -  Singer Elton John has confirmed that his son will undergo a paternity test in a bid to determine whether the singer or his partner David Furnish are his biological father.

The couple welcomed Zachary last year with the help of a surrogate mother. Elton revealed they both contributed sperm samples to the fertilisation  process and the two currently don't know which of them is the child'sbiological father.

"Zach will have to know for his medical records. If it's David, I'd be very  proud. It wouldn't matter to me - and vice versa," dailystar.co.uk quotedElton as saying.

He also revealed that Zachary's surrogate mother sent them breast milk via courier.

"The baby's been brought up in Los Angeles for the first four months so we've had the breast milk 'FedEx-ed' from where she (the surrogate mother) is to Los Angeles every day," he said.