Accusations through press releases and Facebook postings are unusual in Singapore, a country that usually keeps such matters behind closed doors and media freedom within carefully controlled boundaries. And as this comes from within the family of modern Singapore's founding father, Lee Kuan Yew, who was prime minister for three decades, it has gained plenty of attention.
The first salvo came from the prime minister's younger brother and sister, Lee Hsien Yang and Lee Wei Ling, who said on Wednesday they had lost confidence in Lee Hsien Loong and feared that the state's organs would be used against them. Lee Hsien Yang said he and his wife, lawyer Lee Suet Fern, would be leaving Singapore because they felt closely monitored and threatened.
The prime minister denied the allegations, and said he was very disappointed that they have chosen to publicise private family matters. Then late on Thursday, he hit back, saying there are "deeply troubling circumstances" over how Lee Kuan Yew's will was drawn up and asking what role Lee Suet Fern, had played.
There has been plenty of additional back and forth, accusation and denial over the past couple of days. Many on social media website Facebook flooded it with requests for the family to settle the matter out of the public eye.
"It's a personal family matter which should have been settled privately. Not good for Singapore's reputation to air these personal family affairs publicly," Facebook user Selene Zhuo commented on one post from the prime minister.
Another Facebook user Douglas Ho said, "The repercussions are very detrimental to Singapore. This is far beyond a family squabble."
A few used it as an opportunity to criticize the way the government has run Singapore for many years.
"The siblings, in openly attacking their brother, claim to be protecting their father's legacy against Lee Hsien Loong's authoritarian ways, with apparently zero awareness that the system they now fear actually is their father's legacy," journalist and activist Kirsten Han posted on Facebook.
"Pls do not let this affect your health, PM Lee.It's a trivial family matter which happens to lots of families. You are still our caring & loving PM," said Vanessa YC on Facebook.
Some, though, were less understanding.
"When ur siblings cannot trust you, how can we?" asked Facebook user SV Khanthan.
Analysts said it was too early to gauge the dispute's impact on the ruling People's Action Party (PAP). The next general election does not have to be held before April 2021.
"Thus far, the matter is confined to PM Lee and, to a much smaller extent, the government. The party is not yet on the radar screen," said Eugene Tan, associate professor of law at the Singapore Management University.
The heart of the dispute is about whether to demolish the house that Lee Kuan Yew lived in for most of his life at 38 Oxley Road, near the Orchard Road shopping district, capturing the attention of property-obsessed Singaporeans. Lee died in 2015.
"Do I care if 38 Oxley Road is demolished? No, because it doesn't affect the citizens," Facebook user Ethan Lee Yong Sheng posted.
"Do I care if Sungei Market was forced to cease operations? Yes, because a lot of elderly rely on that as their only source of income," the poster added, referring to a flea market that is due to shut next month to make way for future residential development.