The uplifting music video bears the hallmarks of a disaster relief campaign - an all-star lineup, soft focus shots of musicians in a recording studio, smiling adults and children holding hands.

But Unity, released last week, urges help not for a famine-ravaged people but for Sholom Rubashkin, the convicted former manager of Agriprocessors, once America's largest kosher slaughterhouse.

When 51-year-old Rubashkin was jailed this summer for a string of financial crimes, his 27-year sentence shocked many in the Orthodox and the non-Orthodox world.

Since then, his strictly Orthodox supporters have organised dozens of events and maintained a barrage of publicity, culminating last week in the release of the slick, $30,000-budget video featuring more than 30 artists from the Orthodox music world.

Within 48 hours the video, which ends with a plea for donations for Rubashkin's defence fund, had been viewed more than 60,000 times.

Producer Daniel Finkelman - whose brother Eli and his business partner Meir Cohen financed the video - said he was inspired by the We Are the World music video released in February to raise funds for Haiti.

"We are not asking for his [Rubashkin's] release," said Mr Finkelman, 32. "We understand he has to serve his time. But come on - 27 years."

Rubashkin is a prominent member of the Chabad Lubavitch community.

When the Agriprocessors plant, in Postville, Iowa, was raided in May, 2008, almost 400 illegal immigrants were arrested.

Last November, he was found guilty of 86 counts of financial fraud, including bank fraud and money laundering. Later, he was cleared of child labour charges.

Prosecutors called on the judge to impose a 25-year sentence, based on federal sentencing guidelines.

With Rubashkin facing substantial prison time, they dropped their immigration case, saying a further trial would be lengthy and expensive.

Six former US attorney generals wrote to the judge to protest against what they saw as an overly long sentence.

They included Ramsey Clark, a controversial lawyer who has defended Nazis, PLO leaders and Saddam Hussein. Shea Hecht, a leading Chabad Lubavitch rabbi, said the fact that Mr Clark was willing to support a Jewish defendant proved the sentence was unfair.

"When you have a person who's obviously not your friend saying, 'I support you because I think you are being mistreated,' that should have been a bell that went off in everybody's head," Rabbi Hecht said.

In June, Iowa Judge Linda Reade imposed a 27-year sentence, saying that was the minimum according to sentencing guidelines. It included additional time for perjury.

Even some of Rubashkin's strongest critics thought the sentence harsh.

Rabbi Hecht called the immigration raid "an attack on Jews and on kosher food".

"I don't like to use the antisemitism word," Rabbi Hecht said. "But clearly if this was [American chicken manufacturer] Frank Perdue, it would be a different ball game."

But Shmarya Rosenberg, a blogger and long-time critic of Rubashkin who has followed the case closely, said that there is no proof of antisemitism.

Mr Rosenberg said Rubashkin is a victim only of federal sentencing guidelines.

Following the raid, Agriprocessors went into bankruptcy. Last year, it was bought by a Canadian businessman and re-opened as Agri Star.

Mr Rosenberg said that in the wake of the bankruptcy no one in the Orthodox community helped Postville workers who were starving and "being evicted from their homes.This is all about Rubashkin."