The federal government charged the executive director of an Islamic charity with perjury Tuesday, saying he lied about his longtime ties to Usama bin Laden.

The government also charged that the charity, Benevolence International Foundation, sponsored associates of bin Laden who tried to obtain nuclear and chemical weapons for the Al Qaeda terror organization and also plotted to assassinate Pope John Paul II.

Officials said Benevolence International Foundation had links to bin Laden going back decades and gave sizable amounts of cash to his group as well as to charitable causes. Enaam M. Arnaout, 39, the head of the charity based in south suburban Palos Hills, was arrested Tuesday at his home in nearby Justice.

An FBI affidavit does not accuse him or the organization of involvement in those plots. But it alleges that they lied about their ties to terrorists who were involved.

The FBI charged in its affidavit that the charity had links to individuals involved in the 1993 World Trade Center bombing, a plot to bomb U.S. airlines and a plan to assassinate the pope.

"This complaint alleges Benevolence International Foundation was supporting violence secretly," U.S. Attorney Patrick Fitzgerald said.

Arnaout, a Syrian-born naturalized American, appeared before U.S. Magistrate Judge Ian Levin to hear the charges against him. Prosecutors said they would seek to have Arnaout held without bail; the judge ordered him held until a detention hearing May 7.

Benevolence attorney Matthew Piers did not immediately return a telephone call Tuesday after the charges were filed.

Benevolence International Foundation is one of two Chicago-area Islamic charities whose assets were frozen on Dec. 14, with officials saying they were suspected of supporting terrorism. Federal agents also raided their offices that day.

The government is also detaining the co-founder of Global Relief Foundation, the other organization, on an immigration violation.

Both groups have sued the federal government, denying that they have anything to do with terrorism and asking that their assets be released. The Justice Department has been seeking to use secret evidence against both groups.

Benevolence was founded in the 1980s by a Saudi sheik named Adil Abdul Galil Batargy, another bin Laden associate, the document said. The affidavit said control of the group was later given to Arnaout.

Several unnamed cooperating witnesses have said that Al Qaeda members have held positions within Benevolence and the group was used by bin Laden in the early 1990s to transfer money, the affidavit said.

It quoted an unnamed witness as saying that while Arnaout lived in Pakistan in 1989, he picked up one of bin Laden's wives at an airport and allowed her to live in his apartment for a week. It said that bin Laden and his bodyguards arrived a week later to collect the wife.

It said the incident was a sign that bin Laden trusted Arnaout.

The document said that a March 19, 2002, raid on BIF offices in Bosnia turned up firearms, a ski mask, military manuals and a fake passport as well as photos of bin Laden and of Arnaout "handling rifles, a shoulder-fired rocket and an anti-aircraft gun."

According to the affidavit, bin Laden associate Mamdouh Salim had "participated in efforts to obtain nuclear and chemical weapons for Al Qaeda." It said that Benevolence had sponsored his visa for a visit to Bosnia and sponsored him for housing there.

It said he was arrested in Germany and is currently awaiting trial in New York on charges of conspiring to kill Americans, and that he tried to kill a corrections officer while held there. While he was in Bosnia, he stayed at a hotel and was described in writing signed in Arnaout's name as a Benevolence director, the document said.

It said another individual, Mohamed Bayazid, "made efforts to get uranium for Al Qaeda to develop a nuclear weapon." It also said that he obtained an Illinois driver's license showing that the Benevolence office in Palos Hills was his home address.

Bin Laden brother-in-law Mohamad Jamal Khalifa was arrested in California in December 1994 while traveling with Bayazid, the document said. It said a Khalifa alias, Abu Baraa, was found in Benevolence documents seized in the March raids in Bosnia.

According to the affidavit, Khalifa had direct links with individuals involved in the World Trade Center bombing and the plot to kill the pope. It said that the documents seized in Bosnia include a letter written by Wali Khan, allegedly a key figure in the plot against the Pope, to Arnaout, seeking a transfer of money. It said writing on the back of the letter indicated that the money had been transferred.

The document said that in March Arnaout told an FBI cooperating witness that he planned to leave the United States for Saudi Arabia and would not be returning. But he said that only a few days later he was subpoenaed to appear before a federal grand jury and placed under continuous surveillance.

The Associated Press contributed to this report.