A visiting Taiwan national who was found hanging by a bedsheet in his Honolulu jail cell in 2003 was being investigated for possessing written materials on nuclear production, according to government documents obtained by The Advertiser.

The documents confirm that Chen Chi Huang, who ran a tropical fish business in Taiwan but frequently visited his family on O'ahu, was being investigated for national security-related matters at the time of his death.

The FBI last week confirmed that Huang was the target of such an investigation. But an agency representative, citing national security, wouldn't say what was uncovered during the probe or if it remains open.

Since Huang's death in April 2003, the U.S. government has said little about the bizarre circumstances of the case, one with enough intrigue for a novel.

Shortly after arriving on a China Airlines flight at Honolulu International Airport April 12, 2003, Huang was arrested for allegedly lacking proper immigration papers and whisked to the Federal Detention Center without seeing his family. Huang had come to Hawai'i to celebrate his youngest son's birthday and to see another son give the valedictory address at Moanalua High School the following month.

About a week after he was jailed, Huang was found by an inmate hanging from a top bunk in his cell, according to the city medical examiner's report.

He died in a coma four days later, leaving behind a stunned wife and three sons, a perturbed Taiwanese government and many unanswered questions. Taiwan wasn't notified that one of its citizens had been detained by the U.S. until after Huang was found hanging.

Huang's relatives aren't convinced that the wealthy 58-year-old businessman committed suicide. In the weeks prior to his death, his relatives said, Huang talked about many things he was planning to do, including possibly moving to Hawai'i. They said he was looking forward to his son's honors graduation and spending more time with his family. Huang even told a lawyer during his incarceration that he planned to dye his white hair after he got out of jail, family members said.

Relatives dismiss the idea that Huang may have been involved in espionage. "He didn't know anything other than tropical fish and pets," his nephew Aurex Huang of O'ahu said last week. "No way he could be a spy."

QUESTIONABLE PAPERS

The Justice Department documents, obtained by The Advertiser through a Freedom of Information Act request filed in February 2006, indicate that authorities discovered written materials pertaining to nuclear production in Huang's luggage upon his arrival from Taiwan. Among the written materials was a manual, the records say.

When asked through a Mandarin interpreter why an importer-exporter of tropical fish would have such materials, Huang said a friend had faxed him the documents from Hong Kong the previous day, according to a partial transcript from the airport interrogation.

"I don't know the reason, and I have no interest in them," Huang was quoted as saying. "Actually, I haven't had a chance to read them ... I just put it in my luggage."

The transcript says Huang told the federal officer that the same friend downloaded the nuclear-production manual from a computer and gave that document to him a few weeks earlier in Taipei.

"There is no particular reason," he was quoted as saying.

The friend's name, occupation and nationality were redacted from the transcript.

The records do not provide any other information on what kind of written materials Huang had, and neither the FBI nor U.S. Immigration and Customs Enforcement officials would elaborate. Neither agency would say if the nuclear production materials were classified or available from public sources on the Internet. The FBI, however, said it found nothing to indicate Hawai'i residents were in danger.

"Our investigation determined there was no imminent threat," said Pamela McCullough, assistant special agent in charge of the FBI's Honolulu division. She said she could not provide more information about the case, citing national security concerns.

Nicole Huang, Huang's widow, declined comment.

Hawai'i has been the location of at least one case involving allegations of espionage.

A Maui scientist, Noshir S. Gowadia, is scheduled to go on trial next October for allegedly selling military secrets to China. He has pleaded not guilty.

Asked if espionage cases are unusual in Hawai'i, the FBI's McCullough said they are no more unusual than in other areas with a large military presence and people with links to foreign countries interested in obtaining U.S. research, technology and trade secrets. Hawai'i's strategic location in the Pacific is another factor, she said.

"We're a target-rich environment," McCullough said.

She declined to quantify how many espionage cases the FBI typically investigates here, but said such investigations are difficult and usually take several years to complete.

POSSIBLE SETUP

One national expert on espionage matters said the Huang case was baffling and raised the possibility that he was set up.

"I just can't believe that anybody who was engaged in espionage in this day and age would have incriminating, hard-copy documents in their possession when they're transiting a security checkpoint," said John Pike, an intelligence analyst in Alexandria, Va. "It would be horribly bad tradecraft."

On the other hand, Pike said, Huang's answers to the immigration officer's questions seemed odd, and there's still the issue of why he would commit suicide, if that's what happened.

"There may be unanswerable questions about this case," Pike said.

Aurex Huang said he was surprised his uncle was carrying nuclear-production documents. Because his uncle was wealthy, people who did business in mainland China would approach him about possible investments, and perhaps those materials were from someone seeking funding, Aurex Huang said.

Chen Chi Huang's wealth apparently meant he didn't have to be employed.

When he was asked at the airport in 2003 whether he planned to work in the United States, he replied "no" because he was "financially independent."

Yet the Taiwan government was told that Huang was arrested for violating immigration law because he intended to work here but didn't have the required paperwork, according to a Honolulu officer with the Taipei Economic and Cultural Office, the defacto consular office in Hawai'i. The office was not told that Huang was the target of a national security investigation, the representative said, and it had no information on what became of that investigation.

Because the consular office didn't learn about Huang's detention until after he was found hanging, it sent a letter to U.S. authorities expressing concern about the delayed notification. The office also questioned whether Huang was treated appropriately while incarcerated.

Taiwanese authorities were assured that Huang's treatment was proper and he was afforded due process, according to the consular office representative.

If a Taiwan citizen is arrested now over immigration infractions, the Taiwan government is notified immediately, the officer said.

The consular office also was told by the FBI that Huang's death was a suicide, addressing the widow's skepticism that her husband took his own life, the officer said.

Huang left a suicide note in his cell, according to the medical examiner's office, but even that is steeped in mystery. Yueng Huang, who was Chen Chi Huang's oldest sibling, said in a 2004 interview that the suicide note didn't appear to be in his handwriting. She said the part of the note she saw talked about his love of his sons and leaving money to his wife.

Huang and his wife purchased a Salt Lake condo in 1988, but about a month before his death, Huang took his name off the title, according to state records. It is not clear why he did so. The condo is near the Moanalua school where Huang's middle son graduated with top honors in 2003.

In his valedictory speech, the son paid tribute to his father but mentioned that Huang had died several weeks earlier. He didn't mention any details surrounding his father's mysterious death.

Reach Rob Perez at rperez@honoluluadvertiser.com.