A federal judge appointed an attorney Tuesday to advise an Islamic charity director who claims prosecutors are unfairly denying him credit for helping with a terrorism investigation.

Judge Suzanne Conlon also set Aug. 18 for sentencing charity director Enaam Arnaout, a Syrian-born U.S. citizen accused of having close ties to Usama bin Laden (search).

Arnaout, 41, director of Benevolence International Foundation (search), has pleaded guilty to a racketeering charge.

Federal prosecutors say Arnaout has been dishonest and uncooperative, and they have recommended a sentence of 20 years.

He acknowledges he was befriended by bin Laden in Pakistan in the 1980s but denies being an Al Qaeda (searchmember or financing terrorism.

In his plea, he admitted telling donors to his foundation, based in suburban Chicago, that the money was for humanitarian aid while using some to buy supplies for Muslim military units in Bosnia and Chechnya.

Conlon appointed attorney John Theis to advise Arnaout and determine what happened after he pleaded guilty with the understanding that he might get a break at sentencing if he cooperated.

Conlon said she was believed there was a question of fairness concerning "the use of his own statements against him."

Arnaout's attorneys say that because they helped to draw up the plea agreement they could have a conflict if they advised their client on what, if anything, went wrong.