Several years ago, Eli Gerstner, an ambitious record producer on Brooklyn's religious Jewish music scene, decided to venture into the unknown. He had a vision for a young male Orthodox pop group - a "boychik" band.

Gerstner, who lives in Boro Park, assembled a quartet of fresh-faced young men with yarmulkes and sweet-sounding voices. In 2001, The Chevra, which loosely translates as "the group," cut an album of Hebrew songs based on Psalms and prayers and mixed with turbo-charged drums and synthesizers. The boy band's surprise hit, a song and paean for peace called "Yehai Yehai," won Jewish listeners from Brooklyn to Israel.

"That summer, every kid, everyone from 4 to 40 was singing 'Yehai,'" said Nachum Segal, host of the local Jewish music morning radio program JM in the AM. "Girls put on this Beatles Ed Sullivan-type routine, squealing and screaming."

That was then. Now, two albums later, the boy band is at war with itself. Oy vey.

Mr. Gerstner has filed a lawsuit in Brooklyn to quash a rebellion by three of his singers, David Pearlman, Avi Katz, and Donny Baitner. The lawsuit, which moved this month to federal court, accuses the singers of stealing the band and defaming his reputation.

"I never felt so betrayed in my life," said Mr. Gerstner, 24. "Until today, my stomach is turning."

The three men counter that Mr. Gerstner doesn't own the band and never shared profits from CD sales and concerts.

"We're all just nice good boys," said Mr. Pearlman as he sipped coffee in a sweatshirt and yarmulke at a Starbucks in Brooklyn.

Since May, Mr. Pearlman, a 23-year-old culinary school student, and two bandmates have performed without Mr. Gerstner or the band's fourth singer. Mr. Gerstner is seeking a court order to stop them - an order that, Mr. Pearlman said, might bring an end to The Chevra.

"He wants it to be like Menudo," said Mr. Pearlman, referring to the Puerto Rican pop band that replaced members once they got too old.

Unlike Menudo, most New Yorkers have never heard of The Chevra.

Still, the lawsuit bespeaks a familiar story with an Orthodox twist: A band achieves success and begins feuding over control and money.

The case also offers a rare glimpse inside Brooklyn's tiny and hermetic religious Jewish music scene.

Most such cases fizzle because "there's so little money," said Mr. Segal, whose radio program has aired for 20 years. Those that proceed "traditionally go to some kind of rabbinic court," he said.

Mr. Pearlman said the dispute may involve tens of thousands of dollars.

The Chevra topped the charts of a local magazine Country Yossi, which performs a periodic survey of Jewish music sales at stores in New York, a magazine spokesman said. The Chevra became "the hottest group around," the spokesman said.

Mr. Gerstner estimates that the band sold more than 30,000 CDs in America and Israel.

Michael Dorf, executive producer of the New York Jewish Music and Heritage Festival, said he was not familiar with The Chevra. But he said that many new Jewish bands, including Orthodox ones, are cropping up.

"The more I scratch the surface, the more I am blown away," said Mr. Dorf, who founded the Knitting Factory music venue in Manhattan.

Mr. Gerstner, who has his own recording studio, already had recorded two solo albums before The Chevra. "I wanted people to get a taste of what we can sound like," he said.

Band members put up their own money to make the album, Mr. Pearlman said.

"I figured worse comes to worse, we spend a few dollars, get ourselves a nice disc, and show it to our kids in a couple years," he said.

In time, The Chevra's popularity grew, and Mr. Pearlman recalls teenage girls rushing up for autographs - careful, for religious reasons - not to touch the singers.

Eventually, Mr. Pearlman said, he grew suspicious of Mr. Gerstner, who he said refused to open the books. He and two other singers hired a lawyer.

The fourth band member, Dovid Nachman, is not part of the lawsuit and declined to comment.

Mr. Gerstner, who filed his lawsuit in May, insists that he always acted honestly and that money was never an issue. He said he takes credit for writing, orchestrating, and producing the band's music

In a phone interview from Israel, Mr. Gerstner explained that the band's hit, "Yehai Yehai," calls "for abundant peace from heaven." Ironical, he said, given the current situation. But Mr. Gerstner didn't hesitate to assign guilt.

"The people singing my song," he said, "are breaking the peace."