Investigators probe Jeffrey E. Thompson’s possible role in Clinton’s 2008 campaign
Federal investigators are probing Hillary Rodham Clinton’s 2008 presidential campaign as part of an effort to expand their case against a D.C. businessman alleged to have financed below-the-radar political operations, people familiar with the investigation said.

The businessman, Jeffrey E. Thompson, allegedly provided more than $600,000 to fund secret get-out-the-vote efforts to help Clinton in at least four primary states. Prosecutors do not expect to pursue a separate criminal case against Clinton’s campaign, these people said....

...The creation of an off-the-books campaign with the cooperation of a senior campaign adviser could violate campaign finance rules if it was determined that the effort constituted an undisclosed, in-kind campaign donation in excess of federal contribution limits. But legal experts said federal investigators would be unlikely to open a separate case because a five-year statute of limitations has expired....