Former House speaker Newt Gingrich and his wife, Callista, were accused of using his 2012 campaign to promote their books. (Jose Luis Magana/AP)

Former House speaker Newt Gingrich will not face a Federal Election Commission investigation into allegations that he broke federal law by using his 2012 presidential campaign to promote books that he and his wife wrote, documents released Friday show.

As part of an agreement with the FEC finalized Feb. 23, the veteran Republican party leader will shut down his 2012 committee, Newt 2012, in the next few months. The campaign still owes nearly $4 million to more than 100 vendors, who are now unlikely to see full payment.

The FEC’s top attorney recommended in 2013 that the agency investigate Gingrich, but the case languished and the six-member commission eventually deadlocked along partisan lines in June, with the three Republican commissioners voting against an inquiry.

The general counsel’s initial review found evidence of seven violations of campaign finance laws, the FEC documents show. Among the findings: Gingrich’s campaign staff and the employees of his production company at times swapped duties as the then-candidate was holding concurrent campaign rallies and book-signing events.

Gingrich’s campaign was sanctioned for just one violation: failing to properly report a $47,005 debt that the campaign owed him personally for the rental of a mailing list.

Gingrich did not return a call for comment. His former campaign manager, Vince Haley, said in a statement that the settlement “represents the conclusion of a thorough examination by the FEC of NEWT 2012’s compliance with federal campaign reporting requirements.”

“At the conclusion of this examination the FEC asked only that NEWT 2012 reword a single entry in its campaign report with respect to an expenditure that had been previously disclosed by the campaign from its first filing, which NEWT 2012 has agreed to do,” Haley added.

As part of the negotiated settlement, the campaign also agreed to close down within 90 days. It has to file a debt-settlement plan, but it appears unlikely that the committee — which has raised no money so far this cycle — will be able to pay all of its bills.

Among the biggest debts it owes is $977,000 to the air charter company Moby Dick Airways and $287,000 to the law firm McKenna, Long and Aldridge, which is now part of Dentons.

The case dates to December 2011, when The Washington Post reported that Gingrich was holding book-selling events in conjunction with his campaign stops.

The watchdog group Citizens for Responsibility and Ethics in Washington filed a complaint with the FEC alleging that Gingrich’s production company was making illegal in-kind corporate contributions to his campaign.

The FEC’s general counsel found reason to believe the law had been broken, noting that schedules and reimbursement forms provided by Gingrich’s company indicated that its employees were assisting the campaign on the road.

Gingrich’s attorneys maintained that all business and campaign costs were segregated.

The general counsel also found evidence that the campaign’s resources benefited Gingrich personally, noting that his campaign website included more than 80 links to the Gingrich Productions website, along with blog entries promoting book signings and movie screenings. Many of the links went to pages urging supporters to buy books written by Newt and Callista Gingrich.

Noah Bookbinder, CREW’s executive director, called the FEC’s decision to close the case “distressing.”

“This is certainly not consistent with a functioning enforcement body,” he said.