NEWARK -- A West New York man who admitted in federal court that he plotted with others to assist the terrorist organization ISIS was being held under inhumane conditions in a New Jersey prison until recently being moved, his lawyer said in a letter to a federal judge.

Alaa Saadeh,24, pleaded guilty in October to conspiring to provide material support to the Islamic State, known as ISIS or ISIL, by helping his brother fly to the Middle East.

Alaa Saadeh pleaded guilty in federal court to aiding ISIS.

Saadeh, whose sentencing is scheduled for April, was in the Monmouth County Correctional Facility general population but was moved into "protective custody" on Dec. 18 under the order of the U.S. Marshals Service, according to the letter written by attorney Maria Delgazio Noto. Noto said Saadeh had no institutional violations on his record that could have warranted punishment.

A spokesman for the Marshals Service said he would look into why it wanted Saadeh in protective custody.

Once in protective custody, Saadeh was isolated and allowed one hour a day for showering or sitting in a cage, the letter said. The cell was "without heat," Noto said. In addition, Saadeh had no access to exercise, it said, and his visitations were reduced from three per week to one per week, leaving him depressed and unable to sleep.

Such conditions, Noto's letter said are a violation of the U.S. Constitution's proscription of cruel and unusual punishment.

"While certainly prisoners are not entitled to all the amenities available to persons not in jail, the U.S. Constitution places importance on the fact that conditions under which federal inmates are housed be humane," Noto wrote. "In the United States, we do not torture our prisoners no matter how unpopular they may be and no matter what crime they have pled guilty to."

A spokeswoman for the Monmouth County Sheriff's Department said that under protective custody, an inmate is kept isolated for his own safety, and that it wasn't punishment for anything he did while there. The spokesman, Ted Freeman, said the county acted at the marshals' request.

Noto, who wrote the letter last week, said she will not pursue a motion to change Saadeh's incarceration since he has been moved.

According to the U.S. Bureau of Prisons, Saadeh now is being held in the Brooklyn Metropolitan Detention Center. Noto said she believes he is among the general population of inmates.

Saadeh's brother, Nader, also pleaded guilty Dec. 10 to plotting to assist ISIS and is also awaiting sentencing.

Tim Darragh may be reached at tdarragh@njadvancemedia.com. Follow him on Twitter @timdarragh. Find NJ.com on Facebook.