LOS ANGELES – A regretful Amber Frey wept when she heard her ex-lover Scott Peterson was convicted of murdering his pregnant wife and unborn child – because she doesn’t want him to die.

While she was a key witness in the trial that led to the conviction, she loved Peterson deeply and he still has a place in her heart.

So the realization that Peterson could be facing execution hit her hard, her father told The Post yesterday.

“I could hear the tears in her voice,” after the verdict came down, Ron Frey said.

He added that his daughter “is one of the biggest reasons he was convicted. But she did what she had to do. She couldn’t let this man run around loose.”

But he said Amber is conflicted knowing that because of her testimony, a jury could soon send Peterson to death row.

“She is against abortion and the death penalty,” said Frey, a burly general contractor.

As the jury deliberated, Amber sensed that the jury would convict, so she spent time praying with a support group at the Northpark Community Church in Fresno.

“The purpose of praying and being consoled was she knew her testimony was strong, that she told the truth and that it was a death-penalty case,” her father said. “They suggested they turn it over to God and leave it in his hands.”

The Fresno masseuse spent several days on the stand during Peterson’s five-month trial as prosecutors played hours of wiretapped conversations in which Peterson flirted with Frey and explained how he wanted a simpler life and more time with her.

Peterson never admitted to committing the murders of his wife, Laci, and their unborn son, but jurors may have been swayed by Peterson doting so much on Frey in the shadow of his pregnant wife’s disappearance.

As a principal witness in the trial, which is still active, Frey, 29, can’t talk because she’s still under a protective gag order.

Betty Willis, 78 and the wife of the church’s pastor, told the Fresno Bee that Frey has been strong considering all she’s been through.

“She has a tremendous faith in a power outside of herself, and she leans on that and it carries her through,” she said.

Her husband, the Rev. Bob Willis, told the Bee:

“From my estimation, she is a delightful young woman who really has a deep desire to know God and do what’s right.”

Celebrity media and image consultant Michael Sands said Ron Frey gives his daughter too much credit for Peterson’s conviction.

“I think the real one that deserves the credit is Rick Distaso, because he meticulously tied this case together, all the loose ends,” Sands said. “Amber Frey was a massage girl who just happened to date a married guy.”

However, because she showed so much integrity and made a household name for herself in the mold of Donna Rice and Monica Lewinsky, Sands suggested that Frey’s Hollywood stock could bring her a million-dollar book deal and maybe a development deal for a biopic on Lifetime television.

“She will be known as the woman who came clean,” Sands said.

Amber Frey came forward soon after she saw the first TV report of Laci Peterson’s disappearance and acknowledged to police that she’d been Scott Peterson’s lover – but that at the time, she had no idea he was married.