It said the paper, published in February, 2011, and authored by Dr Melendez and a team of collaborators, has since been withdrawn “with the consent of the authors”.

The NUS confirmed it was aware of the retraction which was “made after it was found that major conclusions could not be supported by the data presented in the paper”.

Question marks also surround figures used in a paper authored by Dr Melendez and other contributors which was published last year in journal Science.

It led to the publication publishing an “Expression of Concern”, so it could “alert our readers to the fact that serious questions have been raised about the validity of findings”. A University of Liverpool spokeswoman confirmed: “We take accusations of research misconduct extremely seriously, and as such have investigated this at a senior level, in line with university policy, as have the other institutions involved.”

She added: “Professor Melendez is currently suspended from his role at the university without prejudice, pending the outcome of the university’s formal processes.”

Confirming it was investigating the work of Prof Melendez, Professor Barry Halliwell, deputy president – research and technology at the National University of Singapore, said: “The university takes research integrity extremely seriously.

“Faculty, staff and students of the university community engaging in research are expected to adhere to the highest standard of ethics and research integrity.”

He added: “NUS is committed to ensuring that all allegations of research misconduct are investigated thoroughly and fairly, within as short a time as possible.”

Research areas led by Prof Melendez include how a protein which occurs naturally in roundworm could treat sepsis – a serious inflammatory condition, caused by the body over-reacting to infection.

He was not available for comment last night.