A British teenager conceived through sperm donation is claiming to have discovered her best friend is also her half-brother.

Georgia Bond shared on social media that she and Jack Bowman learned of their secret connection after they sought out their donor’s details.

“A few weeks ago we both found out we were both able to access details about our donors and donor conceived siblings,” she wrote on Twitter.

Bond went on to say how the pair had always joked about sharing a father.

“We’ve always joked about having the same sperm donor and being the brother and sister we naturally act like," she said.

The Liverpool resident said they began the investigation after Bowman learned he had a half-sister who shared her year of birth.

"Jack received his first telling him he had a sister born in 1998, which resulted in me requesting mine," she said.

"Today we found out we have the same sperm donor so we are genuinely brother and sister after all."

Bond ended the post by encouraging others who have been conceived through sperm donation to track down their information.

"Happiest person ever right now, to all those who are IVF, request your details. Miracles can happen," she wrote.

Bond's original post to Twitter has been liked over 81,000 times with 18,000 shares.

The story has become such a global sensation that Bowman publicly asked his friends on Facebook to stop replying to reporters.

"If any sort of reporters try to get information from you about mine and Georgia's news we would both prefer it if you didn't answer them, or say no to them," he wrote.

Australians conceived by sperm donation must wait until they are 18 years of age, unless they were conceived in Victoria, to learn the identity of their donor. Children conceived in Victoria can access their information at any time.

Anonymous sperm donation in Australia is banned in all states and territories.

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