The trial for Prime Minister Lee Hsien Loong's defamation suit against writer and financial adviser Leong Sze Hian opened on Tuesday (Oct 6).

The trial is set to run for the rest of the week before Justice Aedit Abdullah, with Mr Lee represented by Senior Counsel Davinder Singh and a team of lawyers, and opposition politician Lim Tean representing Mr Leong.

Mr Lee, 68, sued Mr Leong in late 2018 over a public Facebook post the latter shared on his page on Nov 7, 2018, containing a link to an article by Malaysian website The Coverage.

The article alleged that Mr Lee had helped former Malaysian prime minister Najib Razak launder money in relation to scandal-hit Malaysian state fund 1Malaysia Development Berhad (1MDB).

Mr Lee's lawyers said the post contained "false and baseless" allegations that were "highly defamatory", including a purportedly libellous allegation that Mr Lee was "complicit in criminal activity relating to 1MDB".

Mr Leong, 66, said in December 2018 that he had complied with a notice from the Info-communications Media Development Authority on Nov 10 to take down the offending post, adding that he had "merely shared" the article with no comments.

After the suit was filed, Mr Leong's lawyer filed a counterclaim alleging that Mr Lee's libel suit was an abuse of court, but this was thrown out by the High Court and later by the Court of Appeal.

The apex court ordered Mr Leong to pay the Prime Minister costs of S$20,000 in September last year, after reiterating that the argument of abuse of court was not part of the law of Singapore and that a plaintiff has the right to choose who to sue for defamation.

Mr Lee arrived by car shortly past 9.30am on Tuesday, in a grey suit and a pale green tie. He waved to the people in the public gallery when he entered the courtroom. There is a limit of 20 people because of COVID-19 safe distancing measures.

Mr Lim and Mr Leong gave remarks to the media outside the Supreme Court before entering at about 9.45am, with Mr Leong saying he was armed only with the "sword of truth".

Members of the public queued for tickets to the public gallery from as early as 5.30am, and tickets were issued by 7am.

The trial comes after Mr Leong's lawyer was arrested on Friday (2 Oct)for alleged offences of criminal breach of trust and stalking.

He was released later that day.