The author of a controversial French bestseller that alleges indirect U.S. government complicity in the Sept. 11, 2001, terrorist attacks is asking the Senate Banking Committee for help in fending off possible criminal charges stemming from the book in his native Switzerland.

Congressional sources say no such help is likely to be forthcoming. But the matter is a potential source of embarrassment for the Banking panel and its chairman, Sen. Richard Shelby (R-Ala.), who chaired two committees that provided the author with a forum on Capitol Hill — apparently without knowing his full background.

Jean-Charles Brisard, co-author of “The Forbidden Truth: U.S.-Taliban Secret Oil Diplomacy and the Failed Hunt for Bin Laden,” testified once before a closed session of the Senate Intelligence Committee, which at the time was chaired by Shelby. Later, on Oct. 22, 2003, Brisard was part of a panel on terrorist finance that appeared before the Banking committee, now chaired by Shelby.

In an interview, Shelby said he does not know who Brisard is and is not aware of his request.

Since 2002, Brisard has emerged as a major source of information for the international media about terrorist financing and operations. He is also the lead investigator for a group of 9/11 families that is suing the Saudi government in connection with the attacks.

But he is perhaps best known internationally for promulgating the theory — featured in the book and in much speculation since — that the Bush administration provoked al Qaeda into launching a “first strike” against the United States on Sept. 11. The theory calls the attacks a response to threats of military action against Afghanistan’s Taliban government by the Bush administration, which was desperate to build an oil pipeline through the country.

Brisard’s theory has had shown some staying power among people who suspect that the U.S. government had a hand in the attacks of Sept. 11. But it has been widely dismissed by terrorism experts worldwide and was given no attention in recent staff reports from the 9/11 commission that is investigating the attacks.

Sources said Brisard approached the Senate Banking, Housing and Urban Affairs Committee through an intermediary. He sought action from the panel that would protect Brisard from the Swiss government, which is investigating Brisard over allegations that his book made defamatory claims concerning Osama bin Laden’s brother Yeslam, who has a Swiss passport.

Yeslam, who claims he has not seen or heard from his estranged terrorist brother since the early 1980s, has sued Brisard and his co-author, Dasquie, for nearly $25 million. But the plaintiff is also seeking criminal charges against the authors in Switzerland, where defamation can be subject to criminal prosecution.

According to one knowledgeable source, Brisard’s go-between wants the committee to tell the Swiss government that witnesses enjoy a measure of immunity from prosecution for testimony provided to Congressional committees, and to indicate that lawmakers would be offended by any future prosecution of Brisard, who provided Capitol Hill with the same information that is in his book.

Testimony from witnesses before Congress enjoys broad protections from civil suits in the United States, but would provide no presumption of immunity for someone being sued or prosecuted overseas, legal experts say. At the same time, someone provided the same information to a Congressional committee that is in his book — even one published in the United States — would not be entitled to immunity from civil suits.

Andrew Gray, a spokesman for the Banking committee, refused to discuss Brisard’s request for help from the committee, saying only, “We do not intend to become involved.”

Gray described Brisard as someone with “a great deal of experience” in the area of terrorism financing — a matter on which the committee plans to issue a report in the near future. Gray stressed that Brisard is only “one witness among many” before the committee.

“What we’ve tried to do on the committee is try to create as complete a record as possible on terrorism finance and money laundering,” Gray said. “[Brisard’s] role is filling in a small portion of that.”

Brisard did not respond to numerous messages left at his office in Switzerland over several weeks. Asked about the author’s effort to win protection from the banking committee, a Brisard assistant, Daniel Martinez, said, “Jean-Charles has no comment.”

According to a transcript of the Oct. 22 hearing, Shelby lauded the author for having “written and studied extensively, not only regarding the [9/11] attacks, but also generally concerning the movement of funds necessary to support terror organizations.”

But the claims made in Brisard’s résumé are a matter of some dispute. A former president of the United Nations Security Council, Alfonso Valdivieso of Colombia, has vociferously denied that he ever asked Brisard to write a report on terrorism, as Brisard has repeatedly claimed. A committee within the U.N. has since confirmed that no individual or entity inside the world body commissioned Brisard to prepare such a report.

The author and his co-author, Guillaume Dasquie, have also faced libel actions in several countries, including Belgium, England and Switzerland, which banned his book in late June. In January, the High Court of England entered judgment against Brisard after he failed to mount a defense. Brisard and Dasquie have had a falling out and parted ways, sources said.

And at the French multinational conglomerate Vivendi Universal, where Brisard said he was once director of corporate security, a source said Brisard had actually been hired to track mentions of the company on the Internet. It is unlikely that he ever served as an “adviser” to Sen. Marty Wirth (D-Colo.) — another claim from the bio posted on the Web site of his U.S. publisher, Nation Books — since no such lawmaker ever existed. (There was a Sen. Tim Wirth from Colorado, but Brisard’s name never appears in Congressional staff listings published during Wirth’s Senate tenure.)

“His bona fides are questionable — and that’s on both sides of the Atlantic,” said Wayne Madsen, an independent journalist who wrote an introduction for the U.S. publication of “The Forbidden Truth.”

Madsen, who is an associate of Dasquie’s and claims never to have met Brisard, added, “I think he’s a loose cannon, and I think the French government is embarrassed by this guy. Brisard is not very well-regarded by the intelligence community in Europe. I don’t know if Shelby knew about that.”

Andrew Cochran, an expert on terrorist financing who served until 2004 as chief counsel at the House Financial Services Committee, said he had never even heard of Brisard before last week.

“We never got any information from him,” Cochran said. “He was never a witness before our committee.”

The Web site maintained by Motley Rice, the South Carolina-based law firm that is suing the Saudi government on behalf of some 9/11 families, said Brisard also testified in closed session before the Senate Intelligence Committee, which Shelby chaired until the 108th Congress.

According to the firm’s Web site, Brisard read Intelligence Committee members a report on the economic network of the bin Laden family that had been “commissioned” by the government of France, and claimed that French President Jaques Chirac “delivered [a copy] to President Bush in person.”

The Intelligence Committee did not respond to requests for comment.

Brisard has shown a knack for appearing, Zelig-like, at the front lines of international terrorism, particularly in instances where international news organizations need an expert to connect the dots.

After the terrorist bombings in Madrid on March 11, Brisard was the sole identified source in early wire reports — ostensibly based on internal Spanish intelligence — that linked the attacks to Abu Musab al-Zarqawi, the man U.S. officials have cited as a key link between al Qaeda and Saddam Hussein’s former regime in Iraq.

In Bosnia, it was Brisard who turned up the reknowned “Golden Chain” document, which purported to list 20 of al Qaeda’s top financial providers — all of them prominent Saudis.

Suzanne Nelson and Kara Rowland contributed to this story.