Ms Ho Ching, wife of Prime Minister Lee Hsien Loong, has been accused by her husband's brother Lee Hsien Yang of taking away documents belonging to Mr Lee Kuan Yew while he was gravely ill and hospitalised in February 2015.
Mr Lee Hsien Yang yesterday turned his latest attack on Ms Ho and the National Heritage Board (NHB) in the ongoing dispute over the future of the late Mr Lee's house in Oxley Road, which had spilled into the public domain last week.
His initial Facebook post charged that Ms Ho had "helped herself" to several of his father's papers, and it was to lead to a series of updates into the night.
He had to edit it after he was told that she was not in Singapore on Feb 6, 2015, the date he accused her of taking away the papers.
Later, the NHB said the date he cited was incorrect, owing to a clerical error.
It led to another Facebook post in which he said the removal of the items would then amount to theft because they were taken away after his father's death in March, without the approval of the estate's executors and trustees.
The papers he said Ms Ho took were: A telegram sent by Mr Lee Kuan Yew in 1958; a letter from J Laycock, founder of law firm Laycock and Ong, where Mr Lee had worked as a young lawyer; a memo from the director of posts dating to the 1950s; and a document from Cambridge University Reporter, a journal of the university's official business.
Mr Lee Hsien Yang said the items were handed to the NHB "under the auspices of the Prime Minister's Office (PMO)", and were "ostensibly on loan".
"She had no business doing this when LKY (Lee Kuan Yew) was in ICU (intensive care unit), and it is deeply troubling that someone can represent the PMO despite holding no official position," he said.
He added that Ms Ho had taken the papers on Feb 6, 2015, based on a list of items from the NHB. He uploaded a photo of the list along with his post.
Ms Ho, however, was accompanying PM Lee on an official visit to Germany and Spain from Feb 1 to 6 that year. According to news reports on the official visits, PM Lee and his wife left Spain on Feb 6. They returned to Singapore on Feb 7.
Mr Lee Hsien Yang revised his post after Channel NewsAsia reported that Ms Ho had been out of the country on Feb 6.
He said: "In that case, since this official NHB document lists Ho Ching as the PMO point of contact, can she please identify the subordinate she instructed to take our father's belongings?"
NHB, following media queries, confirmed later in the night that the items on the list were on loan from the PMO to NHB.
But it said the date the papers were received was April 6, and not Feb 6, as indicated on the list.
"This was a clerical error. NHB has a receipt for the items on loan from PMO dated 6 April, 2015," an NHB spokesman said last night.
"All the items were loaned to NHB after the late Mr Lee Kuan Yew passed away, to be displayed at the In Memoriam: Lee Kuan Yew exhibition held at the National Museum of Singapore."
To this, Mr Lee Hsien Yang said in a further Facebook post around 11.30pm: "This is even more troubling."
He said that based on the late Mr Lee's will, the estate's residual items such as personal documents fall under the absolute discretion of its executors, who are himself and his sister Dr Lee Wei Ling.
"Unapproved removal of these items, even by a beneficiary, constitutes both theft and intermeddling. Ho Ching is not an executor or a beneficiary to our father's estate. We also still do not understand how she is a proper contact representative for the PMO," he said.