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Police in Singapore have reportedly sought the FBI’s help in a probe into the death of a U.S. engineer last year.

The death of Shane Todd, 31, has been classified as a suicide by hanging, but relatives of the Montana man — who was worried that his employers in Singapore were using him to help China get its hands on sensitive technologies to harm U.S. national security — believe he was murdered to cover up his discovery of the purported plot.

Singapore police have said they asked Todd's family to share any evidence in their possession related to his death, BBC reports.

"If [the Todd family] were not comfortable handing evidence in their possession to Singapore Police Force, they could seek the FBI's help to review the evidence," they said in an emailed statement. "As there has so far been no response to this request, Singapore Police Force has sought the FBI's assistance to engage the family and for FBI to examine the evidence."

Eric Watnik, a U.S. Embassy spokesperson in Singapore, said Monday that the FBI would comply with the request, BBC reports.

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"The request is focused on issues entirely within the United States," Watnik added. "The investigation into Shane's death continues to be led by the Singaporean police."

Todd’s parents met with Sen. Max Baucus, D-Mont., on Friday and are seeking a congressional investigation in their son’s death. Baucus plans to meet Tuesday with Singapore's ambassador regarding the matter, Fox News has learned.

Todd “told us that his life was being threatened,” his mother, Mary, told Fox News Channel on Friday.

Just two days after his final day of work in June and a going-away party with colleagues, his girlfriend found him dead in June 2012, hanging from his bathroom door. Police and the coroner believe Todd hanged himself in the bathroom, leaving two suicide notes on his computer, CBS News reports.

Mary Todd said she immediately doubted the authenticity of the note.

“My son did not write this note,” she continued. “He did not take his own life.”

A spokesperson for Baucus told FoxNews.com on Friday that the lawmaker has arranged a meeting for the family with the State Department. Baucus will meet face-to-face with the Singaporean ambassador to the U.S. this week and has personally weighed in on the issue with top White House officials.

Todd’s relatives have since been pressing U.S. officials to investigate the death following a perceived lack of cooperation from Singapore authorities.

Todd graduated in 2005 with a degree in electrical engineering from the University of Florida and later received his doctorate at the University of California-Santa Barbara. In 2010, he chose a job in Singapore because he was looking for adventure, he told his parents.

He took a position at the Institute of Microelectronics, a Singaporean government research institution, to work on cutting-edge technology involving powerful semiconductors. An investigation by the Financial Times magazine revealed that the technology has other applications desired by China, including applications that can be used to disrupt enemy radar and communications.

Todd’s relatives believe his work was linked to China’s Huawei Technologies, which was cited as a potential national security threat by a U.S. congressional committee last year. Huawei has reportedly denied those claims.

"What has to happen is we need a congressional investigation," Mary Todd said Friday.

Click for more from BBC.com.