A federal appeals court on Monday said that the 17-year prison sentence imposed on Jose Padilla, a US citizen also known as Abdullah al-Muhajir or Muhajir Abdullah, who was convicted of aiding terrorists in 2007, was too lenient.

The 40-year-old was arrested in Chicago on May 8, 2002, for allegedly plotting a dirty bomb. The federal court sent the case back to the district court for a new hearing, saying that Padilla got off too lightly and he should face a harsher punishment.

The case was sent back to the district court for new hearing by a three- judge panel of the 11th U.S. Circuit Court of Appeals.

Padilla on January 2006 was transferred to a Miami jail on charges of criminal conspiracy.

In August 2007, after a three-month trial, Padilla and two co-conspirators were found guilty of terrorism-related charges.

Padilla had been in custody for three and a half years as an enemy combatant without any charges. But when civil liberties groups pressurized, the charges on him was dropped and his case was moved to a civilian court.

Padilla's sentence is substantively unreasonable, Reuters reported quoting the panel, arguing that it failed to reflect his criminal history or adequately account for his risk of recidivism.

Padilla's sentence of 12 years below the low end of the (sentencing) guidelines range reflects a clear error of judgment about the sentencing of this career offender, the panel said.

U.S. District Judge Marcia G. Cooke on Jan. 2008 sentenced Padilla to 17 years and four months in prison. However, prosecutors objected Padilla's sentence.

The appellate panel's majority also decided that Cooke had made several errors in calculating his sentence by 12 years. Padilla also served four years in juvenile detention.

Although some downward variance is allowed in this circumstance, the district court abused its discretion, said the ruling written by the 11th Circuit Chief Judge Joel F. Dubina, who was joined by Judge William H. Pryor.

Before May 2002, Padilla had travelled to Egypt, Saudi Arabia, Afghanistan, Pakistan, and Iraq. He was arrested by federal agents at Chicago's O'Hare International Airport on May 8, 2002, on his return.

Jose Padilla was born on October 18, 1970 in Brooklyn, New York. He later moved to Chicago, Illinois, where he joined the Maniac Latin Disciples street gang. He was arrested several times after he had joined the gang.