Singapore will allow US officials to inspect the work of a research institute linked to a Chinese telecoms firm which Washington suspects of espionage, the foreign ministry said on Thursday.

K. Shanmugam, the foreign minister, told officials on a visit to the US capital this week that no improper transfer of technology took place between the Institute of Microelectronics (IME) and Huawei Technologies, the ministry said.

The IME was thrust into the spotlight last month after a report cast doubt on the apparent suicide of one of its former researchers -- US electronics engineer Shane Todd, who was found hanged in his Singapore flat in June 2012.

Todd's family says he may have been murdered because of a project involving state-linked IME and Huawei, but both have said that talks on a joint project did not progress beyond preliminary stages.

In a statement, the foreign ministry said Thursday that Shanmugam stated in Washington that the IME was "subject to rigorous internal audits, and there had been no illegal transfers of technology".

He also reiterated Singapore's pledge to share evidence in the Todd case with the US Federal Bureau of Investigation (FBI).

Shanmugam told journalists in Washington that "we are very happy for a US team to come down and look at the (IME) projects, and it will be very clear that there was no transfer of technology".

Todd was winding up a stint with the IME and preparing to return to the United States when he died at the age of 31.

His parents dispute a Singaporean autopsy report that he committed suicide, saying they found computer files linking their son's work to Huawei.

The final verdict on the cause of death will be determined in a coroner's inquest, in which the Todd family can question evidence. No date has been set.

A US congressional committee last year labelled Huawei and ZTE, another Chinese telecom firm, as potential national security threats that should be barred from government contracts and from acquiring US firms.

The Financial Times reported in February that Todd was working on a project using gallium nitride (GaN), a semiconductor material with military and commercial applications.

"There is speculation by the Todd family that Shane's death was related to a project undertaken by IME with Huawei. Neither IME nor Shane was involved in any classified research project," the institute told AFP.

IME said "the institute did not go beyond preliminary talks with Huawei on a commercial project relating to GaN power amplifiers for base station applications".

It added: "The institute does not have and has never had a project with Huawei on GaN power amplifiers."

It said Todd joined IME in December 2010 as an "entry-level researcher" for another programme and was transferred to the GaN research group in July 2011 after he expressed interest in the "new and frontier" project.

"Shane did not have prior experience or expertise in the field of GaN," IME said, adding that he had worked as part of a team that was supervised by a programme director.

IME also said the US was welcome to conduct an audit of its internal processes.