An 85-year-old former US Army mechanical engineer was arrested Tuesday on charges he slipped classified documents about nuclear weapons to an employee of the Israeli Consulate who also received information from convicted Pentagon spy Jonathan Pollard, US authorities announced. Ben-Ami Kadish was charged in US District Court in Manhattan with four counts of conspiracy, including allegations that he disclosed US national defense documents to Israel and acted as an agent of the Israeli government. At a court hearing Tuesday afternoon, Kadish, who was wearing black sweatpants, was released on a $300,000 property bond. He was required to surrender his passport and can travel only in New Jersey and southern Manhattan. A potential preliminary hearing is set for May 22. Prosecutors say Kadish, a US citizen who worked at an Army base in New Jersey, took home classified documents for six years and let the Israeli photograph them in his basement. Those documents included information about nuclear weapons, a modified version of an F-15 fighter jet, and the US Patriot missile air defense system. A criminal complaint said Kadish confessed to FBI agents on Sunday that he had given the Israeli between 50 and 100 classified documents and accepted no cash in return, only small gifts and occasional dinners for him and his family. Kadish admitted to the charges in court, saying that he wanted to help Israel. Calls requesting comment from the Israeli consulate in the United States were referred to officials in Israel. The Prime Minister's Office referred queries on the matter to the Foreign Ministry. Foreign Ministry spokesman Arye Mekel said: "We know nothing about it. We have nothing to say." Kadish worked at the Armament Research, Development and Engineering Center at the Picatinny Arsenal in Dover, New Jersey. On numerous occasions between 1979 and 1985, the agent provided Kadish with lists of US national defense classified documents he was interested in, according to the complaint. Kadish worked at the military facility from 1963 through 1990. The complaint described a close relationship between the two men that continued beyond 1985, and included telephone and e-mail conversations exchanged as recently as Sunday. The unidentified Israeli agent - since identified in Israel as Yossi Yagur - was described in the complaint as a one-time employee of Israeli Aircraft Industries, which since at least the late 1970s has been a defense manufacturing contractor for the Israeli government. The company is now known as Israeli Aerospace Industries. From July 1980 through November 1985, Yagur worked for the Israeli government as the consul for science affairs at the Israeli consulate in Manhattan. The two men were introduced by Kadish's brother, who worked with Yagur at the manufacturing plant in Israel. The research center where Kadish worked housed a library of documents, including many with classified information related to US national defense. From 1979 through 1985, Kadish signed out at least 35 classified documents, according to the complaint. Kadish told the FBI that he knew that one restricted document he provided to Yagur included atomic-related information and that he did not have the required clearance to borrow it, according to the complaint. Prosecutors say Yagur called Kadish on March 20 and told him to lie to federal law enforcement agents who were investigating possible espionage. "Don't say anything. Let them say whatever they want. You didn't ... do anything. ... What happened 25 years ago? You didn't remember anything," Yagur allegedly told Kadish in Hebrew. In addition to the spying counts, Kadish is charged with conspiring to hinder a communication with, and to make a materially false statement to, a law enforcement officer. Those charges stem from the March conversation. Yagur left the United States in November 1985 and has not returned, according to the complaint, which described him as the same Israeli to whom Pollard provided classified information. Pollard, a former civilian intelligence analyst for the US Navy, pleaded guilty to transferring military secrets to Israel while working at the Pentagon. He is serving a life sentence in a US federal prison. US State Department spokesman Tom Casey said that more than 20 years ago, when the Pollard affair emerged, the US said that it had not expected such conduct from a close ally and that the same applied in the Kadish case. Pollard's wife, Esther, a vocal critic of both the US and Israeli governments' handling of her husband's case, said there was no connection between Kadish and her husband, and expressed concerned that the new case "could result in a further delay in Jonathan's release from prison." "This kind of propaganda plays right into the hands of the people in Israel who are not interested in Jonathan's release," she said. The Kadish story, she added, was no different from other reports that have been used in the past to embarrass Israel, and called upon Prime Minister Ehud Olmert "not to be distracted by this case from what he should be doing and that's bringing Jonathan home." She said she was worried that Olmert might now decide that it was "too delicate a time" to make a serious effort to bring Jonathan home in honor of Israel's 60th birthday celebrations. Gerrie Bamira, the executive director of the Jewish Federation of Greater Middlesex County, in which Kadish's home in Monroe Township is located, said she knew Kadish and his wife, Doris, through their supported of the Federation. "Information is still being gathered with respect to this case, and we look forward to the due process of law," Bamira said. "Individuals are innocent until proven guilty." According to some accounts, Kadish was born in Connecticut and moved to pre-state Israel, where he fought with the Hagana. Other accounts say he served in the American military during World War II. Michal Lando contributed to this report.