The factory owner, played by Alison King, will be subjected to a physical and sexual assault by Frank Foster after he suspects she is cheating on him with Peter Barlow.
Carla will consider leaving Frank prior to the attack, but feels she owes him after he invested in her business and takes the blame for a car accident she is responsible for, The People reports.
"What Frank does to Carla will make the way she suffered at the hands of her psycho ex-husband Tony seem innocent," a source said. "Carla totally ignores all the early warning signs of Frank's twisted personality, even the fact that he has been accused of attempted rape.
"But she ends up suffering terribly. The scenes will be, without question, the most violent seen on the cobbles. The bosses are hoping that they draw in huge audiences in the coming months, but they must tread carefully to make sure this is handled well.
"The producers have spoken with domestic abuse charities and will make a point of advertising their helplines. They know that this storyline will distress people."
The plot will be a prominent storyline over the summer and air after the 9pm watershed during a week of special episodes.
Tracy Barlow will offer to give Frank a positive character reference in court, while Peter's marriage to Leanne suffers when details of his friendship with Carla come out.
Frank, played by Andrew Lancel, has already attacked Maria Connor (Samia Smith).