Four House Democrats sent a letter to US President George W. Bush on Thursday urging him to provide them "with information that will clarify the circumstances" surrounding the FBI's investigation into AIPAC.
"While we certainly wish to see that justice is served, egregious press leaks and reports of a questionable sting operation by the FBI raise serious concerns about the integrity of the AIPAC probe," the lawmakers wrote.
They cited a report in The Jerusalem Post earlier this month, which said the FBI had planted what was described as "classified" information with AIPAC employees to see if they would pass it on to Israel.
The information outlined a plan by Iranians to kidnap Israelis operating in northern Iraq.
"If true, such tactics raise formidable questions about the motives, direction, and very premise of the AIPAC investigation," the letter said.
The four also expressed concern that the "sensationalized media frenzy surrounding the investigation" could feed mounting anti-Semitism and anti-Americanism throughout Europe and the Middle East.
The letter was signed by Reps. Robert Wexler of Florida, Robert Menendez of New Jersey and Eliot Engel and Gary Ackerman of New York.
Several weeks ago, the FBI issued subpoenas to four senior AIPAC officials to testify before a grand jury in Virginia. They were informed that they would be asked to testify in late December but a court date has yet to be set.