LOS ANGELES – A crazed stalker with a fatal attraction to Michael Douglas terrorized his wife, Catherine Zeta-Jones, threatening to “cut her to bits” or blow her up “so pieces of her head look like President Kennedy’s,” according to bombshell court testimony yesterday.

Douglas and his movie-star wife took the stand to reveal terrifying details from phone calls and letters they said were written by aspiring psychologist Dawnette Knight, 32.

In a case that seems almost ripped from the script of Douglas’ chilling 1987 film “Fatal Attraction,” Knight allegedly took up her poisoned pen because she was infatuated with the 59-year-old actor.

The letters threatened that Zeta-Jones’ murder would be “the biggest entertainment story of all time” and accused the sultry actress of having sex with George Clooney, her co-star in “Ocean’s Twelve,” and “marrying Michael for his money.”

Several letters, which Zeta-Jones read aloud in court, referred to cutting or slicing her up “like Sharon Tate,” the Charles Manson victim – or “slashing her throat like Nicole Simpson.”

“We are going to slice her up like meat on a bone and feed her to the dogs,” said one letter.

Another, a mock obituary, had the word “good-bye” next to Zeta-Jones’ picture and called her a “whore gold digger” who would be “solemnized ASAP in a Catholic Church in Wales.”

Douglas testified that at first he tried to spare his wife the horror of the threats, hoping the police could deal with them quietly. “I was shocked, scared and stunned,” Michael Douglas said. But he decided to keep it quiet. “I did not want to create a furor,” he said.

And he did not tell Zeta-Jones. “I felt it would upset her tremendously without having any form of results,” he said.

Between reading the letters, Zeta-Jones also talked about the nightmare at the hearing, held to determine whether Knight should stand trial.

“It’s really hard to keep telling you how I feel. I’m running out of words,” said a gutsy Zeta-Jones, who stared down Knight between recounting the grisly threats that left her with breath-stealing panic attacks. “It’s so satanic a terrorist threat. I can’t imagine how a sane human being could hold these images in her head.”

The stalker is accused of terrorizing the Oscar-winning Welsh actress for more than a year, tracking her around the world.

Knight admitted being “infatuated with Michael Douglas” in a letter of apology she wrote to Zeta-Jones after her arrest in June, but she pleaded not guilty to all charges.

Knight, who is being held on $1 million bail, is charged with one count of stalking and 24 counts of threatening Zeta-Jones between January 2003 and May 2004. If convicted, she could face 19 years in prison.

The alleged stalker even tracked down Zeta-Jones in Amsterdam, where she was shooting the yet-to-be-released “Ocean’s Twelve” in May and phoned death threats to her hotel, triggering horrible panic in the star.

In court, the 35-year-old actress said: “I felt like I was about to faint. I couldn’t breathe. My hands were sweating and tingling. I called my husband and told him, ‘I think I’m going to have a heart attack or a stroke. I have to see a doctor.'”

Zeta-Jones was “joyed and relieved” when Knight was caught and jailed, but “it will affect me for the rest of my life,” she said, wiping a tear with her finger.

Knight played with the braids in her hair as Zeta-Jones spoke.

The threat letters were sent to friends and relatives of the glamorous Hollywood couple. Some of the earliest ones went to the home of Michael’s father, Kirk Douglas, who did not tell his son right away in an attempt to shield the stars.

Michael Douglas was touched by his dad’s courage. “I was deeply concerned for him because he’s 87 years old and he was trying to protect Catherine and myself, and I was concerned about the stress this was putting on him,” he said.

Douglas first learned of the death threats in March 2004, when a call was made to a Bermuda hotel owned by Douglas and his mother. The desk clerk who took the call said “a woman with a Southern-type accent said she was going to kill Catherine,” Douglas testified.

After Douglas learned of the previous threats, he spoke to police, who said he had to tell Zeta-Jones.

The stars were particularly chilled by some of the stalker’s personal knowledge of them.

One letter described the front hall of the Douglas’ apartment in detail. Another described a nanny who had worked for them. “The proximity made us terrified,” Michael said. I felt very vulnerable.”

Knight’s defense attorney Richard Herman tried to make light of the threats, and suggested to Douglas that female stalkers “are not dangerous.”

Prosecutor Debra Archuleta later countered, to objections from Herman, “Wasn’t that the premise of ‘Fatal Attraction?’ And she was very dangerous!”