The process audit of Singapore's Institute of Microelectronics (IME) offered by IME on a voluntary basis to the US government has been successfully completed, the city-state's Ministry of Foreign Affairs said Monday.

The US officials who came for the audit were "satisfied" with the audit, the spokesman of the foreign ministry said in a statement.

The process audit was relating to a US researcher Shane Todd's death in Singapore. He was a employer of the IME and was found hanged in his Chinatown apartment in June last year.

A coroner's inquiry into Todd's death in this July found that the researcher was suicide by hanging. His parents, however, insisted that it was impossible for their son to take his own life and suspected foul play.

They alleged that their son lost his life over a research collaboration between the IME and Chinese telecommunications equipment giant Huawei Technologies.

The judge said in July that there was no evidence to suggest that Todd had been involved with any sensitive research as part of his work at the IME.

The US Embassy in Singapore had then said: " The inquiry into Dr Todd's death was comprehensive, fair and transparent."

The foreign ministry said on Monday that the offer of the process audit was conveyed by Minister for Foreign Affairs K Shanmugam to US Secretary of State John Kerry in March.

The offer was made "in the spirit of cooperation and openness to satisfy the US that allegations of illegal transfers of US technology from IME to the Chinese company Huawei were completely untrue and without basis," said the spokesman.