A family feud being played out in public between Singapore's prime minister and his siblings took an acrimonious turn Friday, with accusations their late father's will had been tampered with.

Tightly-ruled Singapore has been transfixed for days by the bitter row raging among the offspring of revered founding leader Lee Kuan Yew, a family that is the closest the city state has to royalty.

Allegations of cheating, lying and dynasty-building have been hurled, with claims Friday his will had been altered without his knowledge 15 months before he died.

"I continue to have grave concerns about the events surrounding the making of the Last Will," Prime Minister Lee Hsien Loong wrote on his Facebook page.

"I am not aware of any facts which suggest that (the elder Lee) was informed or advised... about all the changes that were made when he signed the Final Will."

The premier's sister, Lee Wei Ling, shot back, releasing a trove of private family emails disputing the claims.

The row centres on a clause in the will that says Lee senior's house should be "demolished immediately after my death". 

Lee feared the pre-World War II bungalow could become some sort of shrine to a man credited with transforming Singapore from a backwater entrepot into one of Asia's richest countries.

He is said to have wanted to avoid the kind of personality cult that can develop around strongman leaders.

But his two younger children say their prime minister brother is attempting to block that demolition, and is looking to exploit their father's legacy to bolster his own prestige and to establish his son as a future leader.

Wei Ling in her own Facebook posts released private email exchanges "as further evidence... establishing that LHL's (the prime minister's initials) allegations are false".

On Friday, Hsien Yang also said on Facebook that their father, a Cambridge-trained lawyer, signed his initials under the demolition clause and posted a picture to prove it.

Source: AFP