[3][2][4] He is a founder and manager of online journalism outlet New Naratif and creator of The History of Singapore podcast, which originally ran as a radio show on BFM 89.9.

[9] At the age of 16, Thum represented Singapore in four swim races at the 1996 Summer Olympics in Atlanta, but did not make it past the heats in his individual butterfly or team medley and freestyle events.

[16] Since 2014, Thum has been a research associate at Oxford's Centre for Global History; a fellow of Green Templeton College; and the coordinator of Project Southeast Asia.

Thum argued that these justifications were false claims made by politicians of the ruling People's Action Party (PAP) for the purpose of political gain.

[32] In response, Chong argued that Thum had chosen to make a political point in his written submission to the Select Committee, and must expect to be questioned about his claims.

[31] Chong also accused Thum of having "engineered" the open letter in support of himself, calling it a "coordinated attempt, with foreign actors involved, to try to influence and subvert our parliamentary processes".

[34] According to The Straits Times, "this is the first publicised case of a proposed incorporated entity having its application rejected due to foreign funding for domestic political activities.

[35] On 1 May 2018, Select Committee chairman Charles Chong noted that Thum and Philip Kreager – both trustees of Oxford's Project Southeast Asia – were directors of OSEA-UK on the British government's company registry.

[36] On 30 August 2018, Thum, Tan Wah Piow and others met Mahathir Mohamad, the Prime Minister of Malaysia, and asked him to take a lead role in promoting democracy in Southeast Asia.

This move received criticism in Singapore, including from Member of Parliament Seah Kian Peng and Law and Home Affairs Minister K. Shanmugam, who said that to invite "a foreign politician, to intervene in our domestic politics ... is an absolute no no".

[37][38] Thum, Kirsten Han and Jolovan Wham, who also met Mahathir, sent letters of complaint to Lee Hsien Loong, the Prime Minister of Singapore, denouncing the conduct of Seah, who is also a member of the Select Committee on Deliberate Online Falsehoods, for making accusations without substantiation.

The trio also urged Charles Chong, the chairperson of the Select Committee, to "take leadership in promoting responsible behaviour and engaging in evidence-based discussion".