Alec Baldwin's alleged stalker has been sentenced to 30 days in prison for heckling him numerous times as he testified against her in court.

Genevieve Sabourin, 41, was held in contempt of court for repeatedly shouting during the 30 Rock star's tearful account of her alleged campaign of harassment.

The French-Canadian actress is accused of leaving up to 55 voicemails a night on his phone and turning up at his homes and at a public appearance.

When she was arrested and charged with harassment and stalking in April 2012, she claimed that she had had an affair with Baldwin that had ended acrimoniously.

Baldwin denies having a relationship with Sabourin, whom he met in 2000. He admitted having dinner with her once at the request of a mutual friend to offer career advice.

At one point during court proceedings an irate Sabourin yelled at Baldwin: "Wow, you're lying. I can't believe you're doing that!"

According to the Daily News she later insisted that she could prove that they had a romance because he had an identifying scar on his hip.

"I gotta prove that I had a sexual relationship. I didn't do anything wrong. He's lying. He's lying!" she exclaimed.

Her contempt of court sentence means that she could spend the remainder of the trial in jail.

She told reporters as she left the court that the strain of the trial had made her "a person who is totally exhausted, humiliated, beat up, destroyed, alone".

"My life is shattered in pieces," she said.