The research engineer's rising career seemed enviable. Shane Todd of Montana was working abroad in Singapore on the latest cell phone and radar technology, coveted by global corporations.

Todd was found dead at age 31, however, in his Singapore apartment last June, and his death has become an international controversy that involves local police, the FBI, an independent forensic analysis and, the parents allege, corporate intrigue found on their son's hard drive.

Singapore police have been investigating Todd's death as a suicide by hanging. They refer to a pulley system around a toilet and over a door in Todd's flat.

His parents, however, say that's absurd and they assert foul play.

Shane Todd's suicide note spoke of family events that never happened, they say.

The family hired a Missouri forensic pathologist, who said photos of their son's body and the Singaporean coroner's report show a different story: homicide.

In the wake of family's revelations about the hard drive, Singapore police on Friday asked the FBI for assistance pertaining to evidence on U.S. soil.

The hard drive ended up in the parents' possession when they packed up their son's apartment, and the mother had thought the device was a small speaker for a computer, she said. They later discovered it really was a hard drive, they said.

Parents Mary and Rick Todd met with a U.S. State Department representative this week in Washington.

The FBI, which earlier said it was watching the case, didn't immediately respond to a request for a comment on the Singapore police announcement.

Eric Watnik, a spokesman for the U.S. Embassy in Singapore, said the FBI will comply with the request. "The request is focused on issues entirely within the United States," he said. "To be clear, the investigation into Shane's death continues to be led by the Singaporean police."

Documents on the hard drive and its login activity suggest their son was working on a project that may have led to his death, his parents say.

The circumstances of their son's death have upended the couple's life in Marion, Montana.

"I just fell to the floor and said it couldn't be my first-born son. It couldn't be," said Mary Todd, mother of four boys, who learned of her eldest child's death from his girlfriend.

Rick Todd, an airline pilot whose wife told him of his son's death right after he flew a long flight, said: "I just, just screamed in the airport."

Shane Todd worked for the Institute of Microelectronics in Singapore from December 2010 until his resignation last May 2, the government research institute said.

He is believed to have died during the overnight hours of June 22 and June 23, the family said.

Though the institute said he was "thought of highly by his supervisor and peers," he disliked his job, his parents said.

That's another reason why his suicide note is suspicious, his parents said: It thanked his company.

The note also spoke of his family drinking Shirley Temples on a beach -- an event that never occurred, they said.

"When I read the note I handed it back to the officer and I said my son may have killed himself, but he did not write this note," Mary Todd said of meeting with authorities in Singapore last year.

The couple also found no evidence of a pulley system: there were no pulleys or holes in the ceramic walls in the bathroom, Mary Todd said.

Shane Todd's apartment appeared as if he were about to return to the United States: clean clothes were folded and boxes packed. A plane ticket sat on the table. He also had a new job lined up, the family said.

Holding a doctorate in electrical engineering, Shane Todd worked for his prominent employer, helping to develop faster, more powerful semiconductors by using the compound gallium nitride.

In his last months, Todd expressed stress about his work and even fear for his life, his family said. He wondered if his work might be illegal or a risk to U.S. national security, his parents said.

After his death, Todd's parents found that his hard drive contained a proposal between the Singapore outfit and a prominent Chinese telecom firm, Huawei, to build a powerful amplifier using gallium nitride technology.

The Todds showed the documents to CNN.

Huawei has been at the center of controversy.

It and another Chinese telecom company, ZTE, were cited last October by the U.S. House Intelligence Committee, which said the two firms "cannot be trusted to be free of foreign state influence and thus pose a security threat to the United States and to our systems."

That comment referred to the firms' business practices, and the committee report said, "the United States should view with suspicion the continued threat of the U.S. telecommunications market" by the Chinese companies.