The long-secret “28-pages” from a Congressional report on 9/11 that are said to explore the alleged involvement of prominent Saudi citizens in helping plan and finance the terror attacks are slated to be released imminently, American officials tell NBC News.

Rep. Adam Schiff, the ranking Democrat on the House intelligence Committee, said the release could come as early as today.

A U.S. official told NBC News the pages would be declassified and sent to Congress Friday. Congressional officials were still deciding how the release would be handled, since the joint committee that produced the pages no longer exists.

The pages contain inflammatory passages but do not prove a Saudi government link to the al Qaeda terror operation, current and former government officials have told NBC News.

Lawyers for some 9/11 family members, and other former officials, argue that the material raises questions about whether prominent Saudis supported some of the Saudi hijackers when they came to the U.S, before the attack.

Related: Ahead of Saudi Trip, Obama Wedged in Debate Over 9/11 Report Secrecy

The campaign to declassify 28 pages of a 838-page congressional report on the worst terror attack on American soil has been ongoing for years. It got renewed attention after former Sen. Bob Graham (D.-Florida) told "60 Minutes" in a recent interview, "I think it is implausible to believe that 19 people, most of whom didn't speak English, most of whom had never been in the United States before, many of whom didn't have a high school education — could've carried out such a complicated task without some support from within the United States."

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For months, a bipartisan group of lawmakers and families pressed the Obama administration to declassify the pages and, in April, the president agreed that his administration would do so. Fifteen of the 19 terrorists involved in the 9/11 attacks were Saudi, a fact the families of victims have said points to that government’s involvement.

Related: On Saudi Arabia Trip Obama Seeks to Quell Tensions

A bipartisan group of lawmakers also have a bill before Congress that would ease the way for Americans to sue foreign countries if they are found liable for terror attacks on U.S. soil — a measure aimed at buttressing the 9/11 families' efforts.

Saudi Arabia, which has pushed for the pages to be declassified as well to help clear up what it calls unfounded allegations, has said the oil-rich nation would be forced to sell off $750 billion in American assets is the legislation is successful. The Saudi government has waged a behind-the-scenes public relations campaign seeking to rebut what they anticipate the 28 pages will allege.

The pages were left out of the public version of the report on the orders of President George W. Bush, who said they could divulge intelligence sources and methods. Also at issue was protecting the delicate U.S.-Saudi relationship, American officials have said.

Rep. Stephen Lynch, a Massachusetts Democrat, has said the pages include evidence tying key Saudis to the plot.

"There are specifics, there are transactions, there are names," Lynch told The Associated Press last year.

Other officials, including the executive director of the Sept. 11 commission, say the classified documents do not prove that the Saudi government knew about or financed the 2001 terrorist attacks, and that making the material public would inflame anti-Saudi sentiment for no good reason.

The 28 pages are "based almost entirely on unvetted, raw material that came to the FBI, material which then was written up in FBI files as possible leads for investigation," Philip Zelikow, the executive director of the 9/11 Commission, told NBC News in April.

However, he said, the congressional panel never was able to follow up those leads. The 9/11 Commission did, and found much of the material unsubstantiated, he added.

"The problem with releasing the 28 pages is not only that it is made up of unvetted investigative material," Zelikow said. "The problem is that to release that would then lead to a clamor to release all the subsequent investigations of these leads, thousands of pages of more material about people who have not been accused of crime."

The 9/11 Commission, which built on the work of the joint congressional inquiry with access to FBI files and secret intelligence, did not exonerate Saudi Arabia. But it concluded in its 2004 report that there was no evidence that the Saudi government funded al Qaeda during the planning of the attacks.

"It does not appear that any government other than the Taliban financially supported al-Qaida before 9/11, although some governments may have contained al Qaeda sympathizers who turned a blind eye to al Qaeda's fundraising activities," the report said. "Saudi Arabia has long been considered the primary source of al Qaeda funding, but we have found no evidence that the Saudi government as an institution or senior Saudi officials individually funded the organization."

Senior officials who have read the 28-pages described the case as weak. Just because Saudi citizens helped the Saudi hijackers in the U.S. doesn't mean they knew about the operation, they said. And the pages contain inaccuracies that were later debunked, but the public reading them wouldn’t know that.

But Graham, a leader of the congressional inquiry and longtime chairman of the Senate Intelligence Committee, has said he sees "a direct line between some of the terrorists who carried out the Sept. 11 attacks and the government of Saudi Arabia."

-- Halimah Abdullah, Luke Russert and Alex Moe contributed reporting to this story