Further questions were raised yesterday about Mr Lee Kuan Yew's (LKY) final will when his younger son Lee Hsien Yang sought to explain how it turned out the way it did.
The last will, he said, was simply a reversion to the first will, and this was done on the "express instruction" of his father. But parts of the first will were left out by mistake.
Responding to media queries in a Facebook post yesterday, he wrote: "Lee Kuan Yew's final will in December 2013 was engrossed on the basis of his express instruction to revert to his first will from 2011."
He added that the seventh and last will "was simply Lee Kuan Yew's first will of Aug 20, 2011, re-executed on his instructions".
The preparation of the late Mr Lee's last will has emerged as a main point of contention in the feud between the Lee siblings over their father's 38, Oxley Road home.
Prime Minister Lee Hsien Loong earlier said their father's last will was made in troubling circumstances, and asked if there was a conflict of interest when Mrs Lee Suet Fern helped prepare it, since her husband Lee Hsien Yang stood to gain from the removal of his sister Lee Wei Ling's extra share in the last will.
The last will also "differed in significant aspects from the first will", PM Lee noted in his statutory declarations to a ministerial committee, a summary of which was released on Thursday.
The last will did not have a gift-over clause, and PM Lee said "there is nothing which suggests that Mr Lee had given instructions for it to be removed".
This clause provides for shares of the late Mr Lee's estate to go directly to his grandchildren, if his sons died before him.
Mr Lee Hsien Yang said the clause was missing as "we took what we understood to be the final version of the 2011 will, without realising that a gift-over clause had been in the executed version of the 2011 will. This was then engrossed without amendment".
He has also said his wife's law firm did not draft any of his father's wills. He added that the last will was drafted by lawyer Kwa Kim Li of Lee & Lee - a claim Ms Kwa denied on Friday when she said she did not prepare the last will.
PM Lee had also questioned why a clause, in which his father stated that he wanted his house demolished after his death, was re- inserted in the last will when it was removed from the fifth and sixth versions of the will.
"There is no evidence that Mr Lee even knew that the demolition clause had been re-inserted into the last will," PM Lee said.
In his post yesterday, Mr Lee Hsien Yang said two lawyers from his wife's law firm - Mr Bernard Lui and Ms Elizabeth Kong - were called to witness the signing of the will as Ms Kwa was not contactable.
"Lee Kuan Yew had read the final will carefully and initialled every page, including just below the demolition clause," he said.
In a subsequent post, he also cited a file note by the two lawyers, who witnessed the will signing at 11.10am.
The lawyers had said that "LKY read through every line of the will and was comfortable to sign and initial every page, which he did in our presence", he added.
He also reiterated that the proper venue to challenge a will is in court.
He said once probate is granted - which means a will is recognised as final and legally binding - the hurdle to challenge a will is considerably higher.
PM Lee had said he did not challenge the validity of the last will in court as he wanted to "avoid a public fight which would tarnish the name and reputation of Mr Lee and the family". To this, Mr Lee Hsien Yang said probate hearings can be heard "in camera", or behind closed doors.