Conspiracy theories about the Oklahoma City bombing have been flooding the Internet, fax machines, talk radio and militia meetings around the country, spun by deeply distrustful minds that cast a broad net of blame from President Clinton to the Oklahoma governor to foreign nations and Jewish groups.

The departure point for these theories is the belief that the federal government is lying about key details of the blast and the media are being duped, if not willingly participating in a coverup. Based for the most part on conjecture rather than fact, the theories have found a ready audience in the subculture of suspicion that gained its first wide exposure in the aftermath of the April 19 Oklahoma explosion.

Federal prosecutors contend that the deadliest terrorist act on American soil was itself a product of the extremist culture. Prosecutors have said that suspects Timothy James McVeigh and Terry Lynn Nichols were so incensed by government overregulation and law enforcement encroachments that they allegedly bombed the Alfred P. Murrah Federal Building, killing 168 people.

Conspiracists have other explanations.

They say that up to six bombs were planted at the site, not just one in a truck parked outside, as investigators have said. Some theorize that the two men charged in the case are actually government-controlled "zombies" used to carry out ghastly plots, like the assassin in the 1962 movie "The Manchurian Candidate." McVeigh's stoic expression in photographs taken after his arrest has been cited as proof that he was under government control. He has been described as a patsy and compared to Lee Harvey Oswald in some conspiracy lore.

Some theorists are circulating documents purported to be affidavits of two Justice Department officials who say they were members of a "Committee of 10" that planned the explosion. Neither the names of the confessors nor their lawyers appear anywhere on the documents.

The range of opinion and sheer magnitude of material espousing alternate views on the bombing has made this "a major moment for conspiracism in this country," said Chip Berlet, an analyst at Political Research Associates, a Cambridge, Mass., think tank that studies right-wing movements. "It is possible that the Oklahoma City bombing will eclipse the JFK assassination in conspiracy lore."

Their prime architects are a stew of self-styled experts, operatives, constitutionalists, gun advocates, states rights supporters, right-wing isolationists and white supremacists. They range from a former Ku Klux Klan grand wizard to a former FBI agent who headed the Los Angeles office. Another claims she once stumbled on a covert operation in which CIA officials, including convicted spy Aldrich H. Ames, and a major U.S. corporation were selling computer equipment to the KGB.

Citizen militias have been among the main disseminators of the theories, and a recent Anti-Defamation League report found that these groups now operate in at least 40 U.S. states, compared with only 13 last fall, and have added about 5,000 members.

The militias also have attracted countless other sympathizers that, coupled with a more conservative political climate throughout the country, have bolstered their clout, according to specialists who track extremist movements.

A common theme is that Clinton or rogue factions within the government ordered the bombing to divert attention from embarrassing issues such as the Whitewater probe and the Branch Davidian siege in Waco, Tex. Theorists have speculated that documents related to Whitewater or Waco were kept in the Oklahoma City federal building and destroyed in the blast; the government has denied this. Others believe that Clinton arranged for the death and destruction so he could come across as a strong leader amid the ensuing chaos and boost his sagging popularity.

More extremist theorists contend that the explosion was planned by federal agents -- influenced by the Anti-Defamation League and the Jewish mob -- to help push antiterrorism legislation through Congress and ultimately stamp out right-wing groups. "SMASH THE CLINTONISTA' JEW-COMMUNIST CLIQUE! FREE AMERICA!" read a widely distributed fax by an extremist group in Fargo, N.D., that also urged people to view a weekly cable television show entitled "White Power."

"The reason for this terrible crime was a pretext for suppressing anti-Clinton, anti-Jew-Communist organizations and . . . slandering all right-wing, conservative, patriotic and white racialist {sic} organizations."

A newsletter entitled "The Omega Chronicle," which is distributed on the right-wing American Patriot Fax Network to thousands of subscribers, contended last month that suspect McVeigh "bears a striking resemblance to an unidentified federal agent whose picture appeared . . . in a recent issue of Soldier of Fortune magazine. If he is in fact this federal agent,' then a completely different element has been added to this tragedy."

Some conspiracists point an accusing finger overseas. They are convinced that the Japanese government undertook the bombing to retaliate against the United States for ordering the CIA to uncork poisonous gas in the Tokyo subway. And political extremist Lyndon H. LaRouche has raised questions about whether the British may have somehow played a role in the blast. Some conspiracists who believe the U.S. government was behind the bombing say that they have received reports of a loud humming sound that was heard in the weeks before the blast that may have summoned McVeigh and Nichols into action.

Conspiracy theories have a history in this country that dates back to the Salem witch trials of the early 1690s. In recent years, evidence of government coverups in controversies like Watergate and Iran-contra fueled suspicions that federal officials deliberately have withheld information from the public when it served their political interests.

A springboard for many of the Oklahoma City conspiracy theories is the contention that the federal government is engaged in a plot to destroy individual rights and liberties and hand over control of the country to the United Nations, which will oversee a "New World Order."

Some theorists believe that proof of a planned U.N. takeover can be found on the back of a 1993 Kix cereal box, which shows an map of the United States carved up into 11 regions. This, conspiracists say, is an illustration of the New World Order plot to reduce the country to departments after the conquest.

By staging violent acts, like the bombing, and creating villains, the government can justify suspending the Constitution, declaring martial law and seizing people's weapons, the theory goes.

These suspicions have led some conspiracists to liken the blast to the burning of Berlin's Reichstag in 1933, widely believed to have been orchestrated by the Nazis as an excuse for Hitler to seize dictatorial powers. Others say that moments before the Oklahoma City explosion, black U.N. helicopters were seen hovering over the building.

Sherman H. Skolnick of Chicago, who contributes to Conspiracy Nation newsletter on the Internet and has been active in suggesting a conspiracy in the death of deputy White House counsel Vincent Foster, is convinced that either Clinton's financial supporters or someone in the government ordered the bombing to obscure the fact that two days earlier Hillary Rodham Clinton was indicted on two felony counts in the Whitewater probe.

The indictment to be unsealed April 19, he said, was delayed by the blast and ultimately quashed because of a legal technicality. "Whatever it was, it was a convenient bombing," Skolnick said in an interview. Although Hillary Clinton has been under investigation in the Whitewater probe, prosecutors have given no indication that they are nearing an indictment.

David G. Hall, who owned a small television station in Ponca City, Okla., and is probing the bombing, said he believes the explosion was the result of a setup by the Bureau of Alcohol, Tobacco and Firearms that went awry. The ATF had been monitoring McVeigh and Nichols because of their right-wing affiliations and had informants approach them about blowing up the federal building, a plot that agents had planned all along to thwart in a moment of public glory, he said. "The ATF wanted to look like the great people who headed off a terrorist attack because they fouled up Waco and the Weaver case in Ruby Ridge {Idaho}," Hall said.

McVeigh was supposed to pull up to the building in the truck that contained the bomb at 3 a.m. on April 19, when nobody was working inside. But for some reason he showed up six hours later, long after the agents had grown tired of waiting and left. "I don't think there was any intent on the part of the ATF for that building to blow up," Hall said.

Former FBI agent Ted L. Gunderson said he believes that the FBI has covered up evidence that a high-tech barometric bomb the size of a pineapple, which set off two explosions, was responsible for the blast, a device too sophisticated for someone like McVeigh or Nichols to build.

"I've been told there are less than 10 people in the world who know how to make this bomb and they would have to have access to classified information because the bomb is classified," he said.

Internet discussions and at least one short-wave radio talk show have alleged the Oklahoma Gov. Frank A. Keating (R) was linked to the bombing. Cited as evidence have been the facts that Keating worked for the FBI for two years after graduating from law school and his brother wrote an unpublished manuscript seven years ago in which terrorists roamed United States blowing things up, including a building in Oklahoma. In the book, a terrorist named Tom McVey is pulled over by the Oklahoma Highway Patrol in a routine traffic stop.

"Now I call that food for thought," one Internet user wrote. Staff researcher Roland Matifas contributed to this report. CAPTION: The launch pad for a new wave of theories is the assertion that the government is lying about key details of the April 19 bombing. Meanwhile, federal prosecutors contend that the attack itself was a product of the extremist culture.