Todd's parents
File photo of Rick and Mary Todd speaking to Reuters during an interview at their temporary place of residence in Singapore. Reuters

A Singapore coroner ruled, on Monday, that the death of American engineer Shane Todd, who worked for Singapore’s Institute of Microelectronics, or IME, in the city-state in June 2012 was a suicide, dismissing his family’s claims that he was murdered in connection with his work related to sensitive technology involving telecom firm Huawei (SHE:002502).

Todd, 31, died of “asphyxia by hanging” and there was “no foul play involved in the deceased's death,” District Judge Chay Yuen Fatt ruled, following two weeks of testimony in May by dozens of witnesses, Reuters reported.

Todd’s death had spawned diplomatic tensions between the U.S. and Singapore, after his parents contested police findings, saying he was murdered in connection with his work on a project between IME, where he worked until two days before his death, and China’s telecommunications major, Huawei. According to the BBC, the coroner’s verdict is final and cannot be appealed.

Todd was researching an advanced semiconductor material called gallium nitride, or GaN, for the project, which involved the transfer of sensitive technology to China, Reuters reported. He was found hanging in his apartment on June 24, 2012, two days after he left his job at IME.

The U.S. embassy in Singapore issued a statement following the verdict, saying the inquiry into Todd’s death was “comprehensive, fair and transparent,” and expressed “heartfelt sympathy” to his family, friends and colleagues.

The coroner said Todd did not possess “confidential and valuable classified information in the course of his employment at the IME,” adding: “The potential GaN power amplifier project did not even materialize. Even if it did, which I did not find, the listed specifications show it would not have violated general export control laws, nor could it have been used for military applications.”

Huawei and Singapore officials have always denied that Todd’s death was linked to the project, saying it did not proceed beyond an initial stage. In June, Senior State Counsel Tai Wei Shyong said there was a “conspicuous absence” of any evidence to support foul play in Todd’s death, according to Reuters.

Sen. Max Baucus (D-Mont.), from Todd’s home state, had pushed for more U.S. involvement in the investigation, after his family’s high-profile campaign challenging the inquiry made by Singapore police after Todd's death.

Todd’s parents walked out of the hearing in May, after an American medical examiner they had hired withdrew his statement that Todd had been garroted, and the judge refused to allow the family to bring in another witness.

The U.S. Congress considers Huawei a security risk, over several concerns including cyber espionage, after an investigation report submitted in October 2012, by Chairman Mike Rogers (R-Mich.) and ranking member C.A. Dutch Ruppersberger (D-Md.) of the Permanent Select Committee on Intelligence.