Media playback is unsupported on your device Media caption Shane Todd's parents say "everything points towards murder"

Singapore has opened a coroner's inquiry into the death of a US engineer whose parents believe he was killed over a China-linked project related to sensitive technology.

Shane Todd's death, in June 2012, was registered as a suicide by hanging.

But his family allege foul play was involved, pointing to work they say was linked to China's Huawei Technologies.

Both Huawei and Mr Todd's employer, a Singapore government institute, reject the claims.

Authorities in Singapore have been working with the US Federal Bureau of Investigation on the case after US officials called for Mr Todd's parents' concerns to be investigated.

The inquiry - which will focus on determining the cause of death - is expected to last until the end of May, after which a verdict will be issued.

Mr Todd's parents, Rick and Mary, are in Singapore and will be testifying.

'Never materialised'

Shane Todd, 31, an electronic engineer, was found hanged at his home in Singapore on 24 June 2012.

At the scene Courtroom 15 at Singapore's Subordinate Courts was tightly packed as local and international media crowded in to hear details of a case which has sparked intense public interest. In an opening statement, the senior state counsel acknowledged that scrutiny, and said the probe would present evidence so a "proper determination" could be made into the cause of Shane Todd's death. The engineer's parents, Rick and Mary, were present - they are expected to testify in coming days. The Montana couple were accompanied by US embassy officials. First to take the stand was Mr Todd's girlfriend, Filipino nurse Shirley Sarmiento, who discovered his body in his apartment. She is among more than 60 witnesses expected to be called. Lawyers representing the Todd family, as well as the company he worked for, will be allowed to examine the witnesses. The outcome of the inquiry into how Shane Todd died will be final, and under Singapore law there will be no opportunity to lodge an appeal.

It was in a Financial Times report in February that Mr Todd's parents raised concerns about the circumstances surrounding his death.

They told the newspaper that what they found at their son's home did not match details in a police report related to his apparent suicide. They also said they did not believe he was the author of a suicide note shown to them by police.

Mr Todd had been employed at the Institute of Microelectronics (IME) in Singapore, a unit under the state-owned Agency for Science, Technology and Research.

He had feared a project he was working on harmed US national security, his parents told the FT.

They picked up an external hard drive at his home, which the FT said contained copies of their son's computer files from IME, including a planned project apparently involving Huawei - a Chinese telecommunications giant - and IME.

Huawei has been labelled a potential national security threat by a US Congressional committee over fears about its ties to China's government and military.

According to the FT, the files detail a project using gallium nitride (GaN), a semiconductor technology that has both commercial and potential military uses.

IME and Huawei said preliminary talks to collaborate on a project did not progress.

'Depressed'

Image caption Mary and Rick Todd told the FT that the scene at their son's apartment did not match police reports

K Shanmugam, Singapore's foreign minister, told Reuters news agency in March that Mr Todd had been " involved in a small project with Huawei that lasted nine months".

"IME discussed a project involving GaN with Huawei. This GaN project has been the subject of much, and sometimes breathless, media speculation," he said.

"The reality is IME and Huawei could not agree terms on the project and thus the project never materialised."

Colleagues of Mr Todd - who had a history of depression - described him as depressed in the months leading up to his death, Reuters reported.

In an opening statement the senior state counsel said that Mr Todd had consulted a psychiatrist in Singapore in March 2012 complaining about "struggles with stress, anxiety and depression due to work and life-related issues".

Mr Shane was at that time prescribed anti-depressant tablets, which were found in his apartment after his death.

Mr Todd's parents told the FT their son had described himself as "anxious" about work before he died, but that he had rejected a suggestion from his mother that he was depressed.