A new book claims to reveal an embarrassing CIA secret - how it lost the highest-ranking Soviet spy ever to defect to the United States.

According to "Escape from the CIA" by Ronald Kessler, Vitaly Yurchenko returned to Moscow after three months, spurning the CIA's promise of $1 million plus a lifetime salary, because the intelligence agency mistreated him.Kessler says Yurchenko, whose redefection made world headlines in 1985, was neither a double agent nor a Soviet plant in the CIA but a man bitter at his treatment.

Kessler also rejects Yurchenko's claims that he was drugged and kidnapped by CIA agents whom he charged had spirited him to the United States from Rome.

Yuchenko went to Rome in July 1985 to investigate a KGB case but disappeared. On Aug. 2 he arrived in the United States and provided the CIA with information identifying Edward Howard, an ex-CIA agent, and Ronald Pelton, a former National Security Agency employee, as Soviet spies.

But on Nov. 2 he escaped from an inexperienced, sympathetic guard at a restaurant in Washington. He returned to the Soviet Union on Nov. 6.

Kessler, the author of several books on spying, told Reuters his conclusions were based on interviews with CIA and FBI agents who handled the case. He also interviewed Yurchenko for 14 hours in Moscow where he is still a colonel in the KGB but said Yurchenko lied to him throughout the interview.

"What I found is that it was not true that he was kidnapped or drugged . . . but it was true that the CIA held him prisoner, in effect under house arrest for most of the time he was here," Kessler said.

"The CIA did not treat him with . . . understanding. He had been traumatized by giving up his country and family. All he wanted was some human understanding and friendship, but instead he was treated with coldness and contempt. This goes back to the way the CIA has historically treated defectors," he said.

Among other reasons for his redefection, Kessler cites former CIA Director William Casey's leaking of the story to the press despite promises that his defection would be kept top-secret.