The espionage case against an FBI agent whose romance with a Soviet spy led to his imprisonment on two life terms will be pursued, the prosecutor said after a court reversed the conviction.

"We may re-appeal and we have other means," U.S. Attorney Robert Bonner of Los Angeles said, apparently referring to requests for appeals court rehearing or Supreme Court review.Bonner, who headed the prosecution in the case, said he would weigh his options after reading Tuesday's decision by the 9th U.S. Circuit Court of Appeals overturning Richard Miller's conviction.

Miller, whose 1986 conviction for spying rested heavily on the results of his lie detector test, was granted a new trial after the court said such evidence should not have been allowed. He is the only FBI agent ever convicted of spying.

The court said U.S. District Judge David Kenyon wrongly allowed prosecution witnesses to relate the questions Miller was asked by a polygraph examiner, the answers he gave, and the examiner's conclusion that he was probably lying.

Miller, a 20-year FBI veteran, was charged with furnishing a classified document to the Soviet Union in return for a promise of $65,000 in cash and gold. He was sentenced to two life terms plus 50 years in prison.

His attorney, Joel Levine, said he was pleased by Tuesday's decision but that the victory comes a little late for Miller.

"We would be more pleased if we didn't have to wait almost five years for a fair trial with a client in custody," referring to the time Miller has spent behind bars since his arrest.