Historian Thum Ping Tjin has been accused of possible involvement in "a coordinated attempt, with foreign actors involved, to try to influence and subvert" Singapore's parliamentary processes.
"This is a serious matter," said Mr Charles Chong, chairman of the Select Committee on Deliberate Online Falsehoods, who laid out the evidence against Dr Thum in a three-page statement yesterday.
He said Dr Thum may have had a hand in crafting an open letter signed by academics worldwide as well as a statement from University of Oxford researchers.
The two documents, which Mr Chong said were similarly worded, defended Dr Thum after he was questioned for six hours last month at the Select Committee's hearings.
"We must protect our independence and the institution of Parliament," wrote Mr Chong, who said the Oxford researchers were presumptuous to tell Singapore's Parliament "how to do its job".
The open letter, published online earlier this month, was addressed to Mr Chong by 284 signatories worldwide - some of whom were academics - voicing concern about a lack of academic freedom here.
Among the signatories were Professor Prasenjit Duara, former director of the Asia Research Institute of the National University of Singapore (NUS) and media studies professor Cherian George of Hong Kong Baptist University.
Separately, a statement was published by seven trustees of the University of Oxford's Project Southeast Asia last month, addressed to the Select Committee.
In yesterday's statement, Mr Chong provided evidence of Dr Thum's involvement in both.
The Parliament secretariat was accidentally copied in e-mails involving the Oxford professors over the statement, in which a Dr Philip Kreager said he had kept in "continuous contact" with Dr Thum. Mr Chong released the e-mails, saying they "lift the curtain on what has been happening in secret".
In one dated April 22, Dr Kreager said: "(Dr Thum) has amongst other things suggested a draft reply for me, which I will turn to on return."
Dr Kreager then referred to a historical workshop he was attending, and added: "There will be a lot of historians from the meeting who will be signing the petition, and I am hopeful that several of them will be circulating our statement and the online letter for signature to their many colleagues here."
Mr Chong said the e-mail strongly suggested that Dr Thum was involved in both the statement and the letter, and showed that Dr Kreager is "actively campaigning for Dr Thum" by circulating the Oxford statement and asking for signatures to the open letter.
Neither statements disclosed the close working relationship between the two, he added. "They give an appearance of spontaneous academic support for Dr Thum in his battle against parliamentarians in an ex-colony... The 'support' seems to have been primarily engineered by Dr Thum himself... in close concert with Dr Kreager."
Mr Chong also pointed out that Dr Kreager and Dr Thum are the only directors of a company called Observatory Southeast Asia UK, which received money from entities linked to American billionaire George Soros and intended to set up a subsidiary to carry out political activities in Singapore. The Accounting and Corporate Regulatory Authority recently refused to register this subsidiary.
"Dr Kreager and Dr Thum are thus not mere academic colleagues," he said. "They are also business partners and fellow activists engaged in a political project directed at Singaporeans."
Mr Chong said Dr Kreager also appears to be Dr Thum's academic sponsor, as he chairs Project Southeast Asia, where Dr Thum is the coordinator. Dr Kreager is also the director of the Fertility and Reproduction Studies Group at Oxford's School of Anthropology, where Dr Thum is a visiting scholar.
It is not clear if those being asked to support the statement and the letter know of the relationship between the two, and of Dr Thum's involvement in their drafting, he said.
On a separate note, Mr Chong said it is still not clear what Dr Thum's precise academic affiliation to Oxford University is, adding that his titles given to the Select Committee thus far have been "inaccurate, non-existent or misleading".
The committee wrote to Dr Thum earlier this month seeking a clarification on his title.The Straits Times has reached out to both Dr Thum and Dr Kreager for a response.