Michelle Grové, 30, claims Herbst, 39, repeatedly abused her, physically and verbally, and loaded video footage of an alleged altercation between them onto YouTube on 9 September.
Grové also claims that she has been in a relationship with Herbst, who is married, since February and that she lived with him in his house in Westdene while his wife and kids lived in Cape Town.
Grové reportedly met Herbst, also known for his role as Ockert in7de Laan and Duncan Haines in Isidingo, in a bar and he told her that he is divorcing his wife.
Grové told Beeld that Herbst "became very jealous and obsessed. He wanted to check my phone all the time to see who SMSes me." Grové also showed Beeld a letter in which Herbst apologises for his obsessive behaviour.
While at a party one night, Herbst reportedly phoned Grové and accused her of lying to him about where she was.
"When I got home, he was waiting for me. He tried to throw me out of the house. I then turned around and all of sudden he hit me over my face. The side of my face was blue," said Grové.
According toVolksblad, Herbst denied assaulting Grové earlier this week. Herbst said he only tried to help her "get on her feet" and that she is "only a friend". He also admitted that at one point he did grab Grové's leg in an attempt to get her off his couch.
Herbst's wife Mia could not be reached for comment.