The dead man's parents, Rick and Mary Todd, are challenging the police's initial findings of suicide and contend their son may have been killed in connection with his work for Singapore's Institute of Microelectronics, where he researched sensitive technology.

WSJ: FBI Backs Singapore View on U.S. Man's Death

They said he expressed concern about a project he was working on for his employers, Institute of Microelectronics (IME) in Singapore, a unit under the state-owned Agency for Science, Technology and Research.

BBC: Singapore seeks FBI help over Shane Todd death