She had told Mr Wewege on August 28 she could not "get any evidence" from Mr Brown because he would not talk to her.
"And it won't help my future by saying that I've been involved in an extramarital affair?"
A month out from the elections, Mr Wewege replied: "Baby but YOU can change the election".
Ms Herzog said Mr Wewege's profile would be withdrawn from the "Top 99 under 33 list pending further review".
She said Mr Wewege was nominated by two third parties but would not disclose their identities other than to describe them as "trustworthy people in the foreign policy and young professionals realm".
Mr Wewege, 28, has gone to ground this week and has not responded to requests for comment.
A South African of Italian heritage, he moved to New Zealand in 2011 and began moving in Auckland political circles where he was described by National Party sources as as affable, charming and a smooth networker who was always "keen for a photo opportunity with anyone important".