'The baby had Asian features, black hair and brown eyes ,' he said, revealing that he and his wife are both 'white blonde folks with blue eyes.'
The man wrote that they immediately raised their concerns with the clinic who organised a DNA test, which revealed that he was not the father.
The pair were offered financial compensation, but according to the anonymous post, it wasn't enough.
'We don't care about race, we are just upset that the baby wasn't both of us, if he was white and not mine we still would have been just as upset,' he added.
Clearly devastated, the man announced that the surrogate was also heartbroken but couldn't afford to keep the baby herself as she already has five children herself.
He then asked other users of the forum whether he was a bad person for wanting to take legal action against the agency and not keep the baby.
The post, which has since been removed, has received more than 4,000 emotional responses, with many pointing out that the baby was still his wife's biological child.
'You bought this child into the world, you now have the responsibility to care for it,' one user wrote.
'Genes don't matter that much. Get over it and learn to love the kid. If you can't do that, you are huge immense a**holes for bringing this child into life and then ditching it,' another commented.
While it is not known where the couple reside, it is illegal to pay someone to be a surrogate in Australia.