Dr Whyte initially told the Herald his response was based on his belief that: "I don't think the state should intervene in consensual adult sex or marriage, but there are two very important elements here - consensual and adult".
"I wonder who does believe the state should intervene in consensual adult acts?"
He said he was "very opposed" to incest. "I find it very distasteful. I don't know why anybody would do it but it's a question of principle about whether or not people ought to interfere with actions that do no harm to third parties just because they personally wouldn't do it."
He did not believe the increased risk of congenital disorders in children from incestuous relationships was a valid reason for it to be illegal.
"The probability of having some problem with the children is greater when the mother is over the age of 35 but I've never heard anyone suggest that anyone over the age of 35 shouldn't be allowed to have sex."
His view was not Act policy and "nobody who votes for Act has anything to fear".
Mr Prebble, a founding member of Act, said he didn't see Dr Whyte's comments as a hindrance to his task of building support for the party.
"Actually in some ways it is useful because it shows Jamie Whyte is not a politician and I don't think the public want politicians. Our enemies will attempt to distort that but I find the guy refreshing and new and I think the electorate is looking for something that's fresh and new.
"He's somebody who's very frank and so when he says things he means it. If you've got a candidate who happens to have been a philosophy lecturer at Cambridge University you can always ask him 'gotcha' questions."
Dr Whyte who was elected Act leader this month but officially takes over from John Banks this weekend said he was not prepared to avoid difficult questions like that about incest as other politicians might.
"Maybe I should, but it seems to me the people who find ways around it and avoid it are being less virtuous than me ... I would have to be inconsistent, I would have to be intellectually corrupt."
Labour MP Shane Jones and National's Judith Collins poked fun at Dr Whyte's comments this morning.
"On one side we've got Colin Craig who doesn't believe in the moon, and he's got this other guy who wants a role in deliverance," Mr Jones told RadioLive.
"What a zoo on the right."
Ms Collins said "there were bigger issues in the world" than incestuous relationships.
"It's the Act Party, and they're known for their interesting and opposite views, and they don't have to be a broad church mainstream party like ours.
"He's speaking as a philosopher, not as a parent," she told RadioLive.
Jamie Whyte on:
Incest: "I find it very distasteful. I don't know why anybody would do it but it's a question of principle about whether or not people ought to interfere with actions that do no harm to third parties just because they personally wouldn't do it.''
Drugs: "Those who have never taken Ecstasy might not know how wonderful it feels.''
Making mistakes: "I'm sure to make mistakes. But it seems to me if I'm honest, I can't make a terribly big mistake.''
