BOSTON, OCT. 19 -- Opening arguments were set to begin here Tuesday in the criminal trial of U.S.A. v. Lyndon H. LaRouche Jr. et al, but, as in almost every other stage of this complex three-year case, there is an unexpected twist.

After a half-hour flurry of tangled motions by defense attorneys and prosecutors at the end of a daylong court session, U.S. District Judge Robert Keeton said he may sever the case of one defendant -- former Ku Klux Klansman Roy Frankhouser, charged with obstruction of justice -- and try him first.

That would delay the obstruction trial of LaRouche and seven associates for at least a month.

Keeton said he will rule on convoluted legal motions Tuesday, the same day that the seven-man, five-woman jury picked during the past month is to start hearing opening arguments. It is the first time the Leesburg, Va.-based LaRouche group has faced criminal charges.

Today's arguments revolved mostly around Frankhouser, of Reading, Pa., a former neo-Nazi who for eight years was a paid security consultant to the LaRouche group.

Frankhouser and a Klan colleague, Forrest Lee Fick -- who was not indicted because of his cooperation with authorities -- told the FBI that for years they told LaRouche followers that they had high-level CIA contacts and were acting as intermediaries between the group and the U.S. intelligence community.

The prosecutors say that in 1984, when the FBI started investigating the group for millions of dollars worth of alleged fund-raising fraud, the two advised the group to send witnesses to Europe and to hide and burn subpoenaed documents -- all alleged offenses for which LaRouche, his followers and Frankhouser have been indicted.

LaRouche and his associates say they followed some of the advice because they believed that Frankhouser and Fick were transmitting orders from the CIA, despite their statements to authorities that they faked their CIA association.

Lawyers say the trial would be a legal nightmare -- and a guilty verdict potentially appealable -- because of differing opinions about the admissibility of evidence, such as Frankhouser's allegedly self-incriminating statements to the FBI and numerous contradictory LaRouche statements.

So, late today prosecutors and defense attorneys ganged up on Frankhouser, saying that they wanted him severed from the others and tried first. Frankhouser's attorney, Owen Walker, also wanted a severance but did not want his clients tried first. The legal issues became so complex that at some points lawyers were rolling their eyes and laughing into their hands.

Frankhouser has denied telling the FBI anything, and he interrupted the proceedings each time prosecutor John Markham referred to Frankhouser's 1986 "confession" to the FBI. "Under torture," said Frankhouser.

Walker, his lawyer, repeatedly told him to "shut up." Walker placed his face on the defense table in front of him as the judge expressed interest in trying Frankhouser alone starting Tuesday. Walker said he was unprepared to mount a defense and must read 100,000 pages of LaRouche group notebooks seized in a raid last year before he can do so.

Meanwhile, security has been stepped up in the federal courthouse, and LaRouche guards spent today checking out the building and the huge courtroom in which their leader will be tried.

LaRouche goes almost nowhere without armed guards because, he says, he is certain that he is in constant danger of assassination by the Soviets. The trial has caused extreme tension in his organization, which contends that jailing LaRouche -- who faces a maximum of five years in jail and a $250,000 fine -- would be an attempt to kill him.

Three of the 13 indicted LaRouche associates are fugitives, and two others already have been severed from this trial. Several in this group have been indicted on charges of credit card fraud in this case. All of the LaRouche associates deny the charges.