Judy Haim is speaking out after an allegation surfaced that her late son, Corey Haim, was sexually assaulted by Charlie Sheen.

In a National Enquirer report released earlier this week, the Two and a Half Men star was accused by one of Corey's longtime friends of sexually assaulting the then 13-year-old actor on the set of the 1986 film Lucas.

"My son never mentioned Charlie. We never talked about Charlie. It was all made up," Judy tells ET exclusively following the publication of the report. "If my son was here to hear all of this he would throw up."

Corey, who starred in a number of popular films in the '80s, died on March 10, 2010 at the age of 38 of pneumonia.

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"I lived with [Corey] in Canada half the time. I knew exactly where this kid was at all times," Judy continues. "I’m fed up ... because you know what, my heart can’t take it. I’m his mother, I’m mourning. My family is freaked out all the way to Israel. Corey’s best friends are freaking out. They’re going, 'What the hell is he talking about?' They all know the truth because my son had a very big mouth. Every time he had an interview he told everybody what drugs he was on, what he was doing. We’ve never heard of Charlie, ever."

Following the report, Sheen's rep told The Hollywood Reporter that the actor "categorically denies these allegations."

As far as what Judy has to say to Sheen, she expresses that "it's very, very sad."

"I will say to Charlie, 'I don’t know you. I don’t know what people are guilty or not guilty,'" Judy says. "'All I know is that from my standpoint I’ve never heard my son mention anything about you. We never talked about you since Lucas. I feel bad because this is a big problem in Hollywood and all over the world. I hope it can be straightened out and I hope that the people that actually have done harm to others are going to be paying the price at the very end of the day."

"I was shocked to see the headline. I am so incredibly fed up," she adds.

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At the moment, Judy feels "sorry for my kid" and adds that he had "such a good heart."

"I swear he had a heart of gold. He had problems, of course, he wasn’t perfect. Who is?" she says. "But you know what? I had cancer in 2009 and I’ve got to tell you he was that kind of a son that took me to every single appointment. He shaved my head when I lost my hair. He vacuumed and cleaned and went shopping. He took care of me, bought me flowers. He did that all of his life. He was a really good son. We had our fights, of course, like everybody else. It wasn’t all great, but overall. I’m telling you he was a loyal friend."

Reporting by Brendon Geoffrion.