A federal grand jury has begun investigating allegations that New York Rep. Michael Grimm received illegal campaign contributions from followers of a New York City rabbi, FoxNews.com confirms.
Subpoenas have been issued, a law enforcement source told FoxNews.com
Followers of Rabbi Yoshiyahu Yosef Pinto, an influential figure in Israel with a headquarters in Manhattan, raised hundreds of thousands of dollars for Grimm when he first ran for office in 2010, according to campaign records. Some donors have since said that they broke rules to donate more cash to the Republican's campaign than allowed by law.
Grimm made statements to media earlier this year calling the allegations against him completely false.
"These allegations are so profoundly absurd that they serve as proof of the coordinated, Democratic smear campaign designed to recruit a stronger opponent to challenge me," Grimm said.
Grimm has repeatedly denied any knowledge that Pinto's supporters were breaking the law to assemble his donations.
Another law enforcement source, without elaborating, told FoxNews.com that Grimm also was under investigation for issues not related to campaign finance, and former FBI agents have been interviewed.
FoxNews.com's Jana Winter and the Associated Press contributed to this report.