WASHINGTON U.S. officials investigating the case of former Los Alamos scientist Wen Ho Lee are focusing on visits he took to Taiwan's leading military research center, the Washington Post reported on Sunday citing sources familiar with the case.

Lee, the scientist at the center of a probe over allegations of mishandled nuclear secrets, told the Federal Bureau of Investigation he was a paid consultant in the late 1980s and early 1990s to a Taiwanese businessman who later helped arrange Lee's visit to the Chung Shan Institute of Science and Technology, the paper said.

The newspaper said investigators were puzzled by Lee's attempts while at Chung Shan in May 1998 to gain remote access to the classified computer system at Los Alamos and while he was denied access, he was able to get into his personal unsecured computer files.

During recent questioning, Lee told the FBI there were some classified files in the directory he accessed but he only extracted unclassified material, the paper said.

The information about Lee's trips prompted the FBI to review Lee's ties to his country of birth as well as his ties to the institute that allegedly was involved in Taiwan's efforts to develop nuclear weapons, the newspaper reported.

While at the Chung Shan Institute in April and May 1998, Lee told the FBI he consulted on issues related to unclassified computer codes and received a fee of less than $5,000, the paper said citing a person familiar with the case.

Lee did not report the payment, which was required by the Los Alamos lab, and made the disclosure during 10 days of questioning that ended Dec. 12. He also spoke at a luncheon at the institute in late 1998, the paper reported.

Mark Holscher, Lee's attorney, told the Washington Post there was nothing improper about his client's trips to Taiwan where he has family. Lee also had received permission from the Los Alamos lab to go to Taiwan for an unclassified speech and consulting, the lawyer said.

Government attorneys have completed two months of questioning of Lee, who agreed to cooperate to end a criminal case against him for allegedly illegally downloading nuclear weapons design secrets at Los Alamos National Laboratory.

U.S. prosecutors agreed to drop all but one of 59 felony charges against Lee if he would tell them what happened to seven missing computer tapes that they alleged contained nuclear weapons design secrets.

Lee has said he destroyed the tapes but never disclosed what happened to them. FBI agents up until recently have been digging through the Los Alamos county dump in what is believed to be a search for tapes.

(Reuter)