The Attorney-General's Chambers (AGC) has said it is looking into a Facebook post by the nephew of Prime Minister Lee Hsien Loong, in which he questioned the independence of Singapore's courts.
In the post last Saturday, Mr Li Shengwu, 32, eldest son of Mr Lee Hsien Yang, said foreign media had been cowed into self-censorship because of previous legal action.
He also included a link to a 2010 New York Times commentary that was critical of his late grandfather, founding prime minister Lee Kuan Yew, and the Government over what it deemed as censorship of the foreign press.
The commentary slammed the International Herald Tribune newspaper for apologising to the late Mr Lee and PM Lee over a column saying Singapore was ruled by a political dynasty.
It also quoted a former general counsel of a newspaper saying that Singapore's leaders had never lost a single libel suit.
Mr Li's Facebook post also had another link to a Wall Street Journal newspaper article giving a summary of the recent Oxley Road dispute, titled "Singapore, a model of orderly rule, is jolted by a bitter family feud".
His post was published by at least two websites - Thoughts of Real Singaporeans and The Independent - and circulated on social media.
The AGC, following media queries, said in a brief statement yesterday morning: "AGC is aware of the post and is looking into the matter."
Mr Li, who is working in the United States, reacted to it yesterday afternoon, saying on Facebook that he was "somewhat surprised" that his post - which was shared on a "friends only" privacy setting - was enough to trigger a response.
He added: "I am surprised that the Singapore Government is so petty. Would they also like to trawl my private Facebook feed for seditious vacation photos?"
Mr Li's aunt, Dr Lee Wei Ling, also commented on the matter yesterday, saying on Facebook that she was surprised by the AGC's "negative reaction to a private post".
"Is there a government servant whose duty is to follow the Facebook activity of all people related to Hsien Yang and I, including our private musings. What Shengwu posted is a common topic amongst Singaporeans who are well informed," she wrote.
"Is this not an example of 'Big Brother' government", she asked, using the famous phrase from George Orwell's novel, 1984, to refer to an authoritarian government which exercises total control over its citizens.
Dr Lee and Mr Lee Hsien Yang had been embroiled in a public dispute with their elder brother, PM Lee, over the fate of their father's home in Oxley Road since mid-June.
PM Lee subsequently delivered a ministerial statement in Parliament on July 3 to address their allegations that he had abused his power.
The feud, which made international headlines, took a conciliatory turn on July 6 when the two younger siblings said they accepted PM Lee's desire to settle the quarrel in private.
The duo also said they would stop posting further allegations and evidence against him on social media, but on condition that their wish and their father's desire to demolish the house at 38, Oxley Road "are not attacked or misrepresented".
Yesterday, Mr Chee Hong Tat, Senior Minister of State for Communications and Information, and Health, was quoted in Chinese daily Lianhe Zaobao as saying that he was "disappointed" with Mr Li's actions.
Mr Chee, who was the late Mr Lee's principal private secretary from 2008 to 2011, added: "Is this respecting Mr Lee Kuan Yew and his values? I don't understand why he continues to launch online attacks, after his father already said he was going to stop doing so."