SINGAPORE - An article published by The Online Citizen (TOC) on Aug 15 has "gravely injured" the character and reputation of Prime Minister Lee Hsien Loong, his lawyers said in court documents.

PM Lee is suing TOC chief editor Terry Xu for defamation over the article and a Facebook post, which his lawyers said contained "false and baseless" allegations, including that the PM had misled his father, the late Mr Lee Kuan Yew, into thinking their Oxley Road home had been gazetted by the Government.

Lawyers from Davinder Singh Chambers had served Mr Xu, 37, the writ of summons and statement of claim at his home in Choa Chu Kang on Thursday (Sept 5).

In court documents seen by The Straits Times, the lawyers charged that PM Lee has suffered loss and damage, and has been "brought into public scandal, odium and contempt".

The TOC article was titled "PM Lee's wife, Ho Ching weirdly shares article on cutting ties with family members".

It had referenced a Facebook post made by PM Lee's sister, Dr Lee Wei Ling, in which she set out a purported sequence of events related to the 38 Oxley Road property.

On Sunday, Mr Xu had received a letter of demand from PM Lee's press secretary Chang Li Lin to remove the offending article and Facebook post by Wednesday.

He had not taken down the Facebook post by the deadline.

Related Story PM Lee sues TOC chief editor Terry Xu over article and Facebook post

The article, which was initially removed on Sunday evening, also reappeared on the TOC website.

Mr Xu also stated publicly that he was not going to comply with PM Lee's demands.

In the statement of claim, PM Lee's lawyers said the article contained "sensational allegations", including that PM Lee had misled Mr Lee Kuan Yew into thinking it was futile for him to keep his direction to demolish the Oxley house.

This caused Mr Lee Kuan Yew to consider other alternatives to demolition, and to change his will to bequeath the house to PM Lee.

The article also alleged Mr Lee Kuan Yew had removed PM Lee as an executor and trustee of his will after it was revealed to him in late 2013 that the house had in fact not been gazetted.

These baseless allegations were "calculated to disparage and impugn" PM Lee, as well as his office as the Prime Minister, the lawyers said.

They noted that TOC's Facebook post had attracted hundreds of reactions and comments, and was shared extensively, which meant the false allegations were disseminated to a wider audience.

The article was also republished on the Internet on various blogs and websites, such as the HardwareZone forum, My Car Forum site and Under The Angsana Tree blog.

PM Lee's lawyers said they will rely on the following facts to recover aggravated damages.

First, the nature and gravity of the libel.

Second, the mode, extent and timing of the publication of the libel.

Third, malice on the part of Mr Xu, as he had published Ms Chang's letter on his website and made the article accessible again.

PM Lee is claiming damages, an injunction to restrain Mr Xu from publishing or disseminating the allegations, and costs.

Mr Xu said in a Facebook post on Friday that he will not be responding to media queries on his case.

He has eight days to file notice in court that he will be defending himself against the suit.

A pre-trial conference is scheduled for Oct 15.