A "lapse of memory" was responsible for confusion over illegal structures at his home on The Peak, Chief Executive Leung Chun-ying said yesterday.
But that was not enough for lawmakers, who demanded he give them a fuller explanation.
He said in a written statement that he had no intention of hiding the facts. However, he said that, in addition to the structures already disclosed, there were others he may also have to demolish at his two houses in Peel Rise.
"I admit there is negligence and there was carelessness when [I] handled the incident ... but hard facts have shown that I had no intention to hide [anything]," Leung wrote.
He had waited until all legal action against him over the illegal structures ended before making the statement.
Pan-democrat legislators said the written statement was not enough, while others said Leung had proved he had no intention to lie.
The Legislative Council's House Committee voted to invite Leung to appear before it to give a further explanation.
Political analyst James Sung Lap-kung said Leung's popularity could now rebound.
"His popularity ratings can still rise if his government can set out policies that benefit the public," Sung said. "But his administration remains at risk of a governance crisis if his future policy initiatives faces any setback."
The existence of illegal structures at Leung's houses came to light earlier this year after he had strongly criticised Henry Tang Ying-yen, his rival in the chief executive election, over a luxurious 2,250 sq ft basement at his Kowloon Tong home.
Controversy over Leung's illegal structures led to calls for him to step down even before he took office in July.
The Buildings Department said in June it had found six illegal structures at Leung's houses - a 240 sq ft basement, the main gate, a 40 sq ft single-storey structure, a cover over a parking space, a trellis and a glass enclosure in the garden.
Yesterday Leung wrote that he might also need to demolish a sauna room, a guest toilet, a retractable roof over the main bedroom's balcony, an expanded laundry room and a locker.
In June he admitted building the glass canopy and trellis, but said the latter replaced a rotten one. Yesterday he wrote: "No matter whether the previous landlord left a trellis, after the home purchase I installed a trellis at House 4 and House 5. A few years later they were turned into a glass canopy and a [new] trellis which were removed in June."
The statement came nearly five months after the structures were spotted. Prior to June Leung had said no unauthorised work had been done at his houses, citing the opinions of professionals.
Leung said he was negotiating with the Buildings Department over the previously undisclosed items and a maid's room.
Civic Party lawmaker Alan Leong Kah-kit said it was not satisfactory for Leung "to speak on his own without letting others cross-examine him'.
Labour Party chairman Lee Cheuk-yan said the affair had shown that "the whole election campaign was based on lies".
Democratic Alliance for the Betterment and Progress of Hong Kong chairman Tam Yiu-chung said he believed Leung had not intentionally hidden any facts.
Engineering-sector representative Lo Wai-kwok said Leung showed in his statement that he had applied for some of the add-ons after moving in, and was thus unaware other works were illegal.
Twists and turns in Leung Chun-ying's accounts of illegal structures
June 21 Ming Pao Daily says unauthorised glass canopy had been found in one of Leung Chun-ying's two houses on Peel Rise. Canopy has been removed by the time report came out. Leung says it was built to replace wooden trellis that was already in place when he moved in.
June 22 The daily tells of illegal trellis in Leung's house next door. Buildings Department finds six illegal structures in both houses, including 8.5 square metre room, metal gate leading to both houses and sheltered parking space of 24 sq metres. Leung apologises, removes trellis and stresses remaining structures had existed before he moved in and he did not know they were illegal. Pan-democrats tell ICAC he has made false claim in election campaign.
June 27 The daily says aerial photos show houses did not have any trellis before he moved in.
June 29 Past owner of houses admits building gate and parking shelter, but not wooden trellis.
July 4 Leung Kwok-hung and Albert Ho Chun-yan file judicial review against his "false claim".
July 5 Executive councillor Barry Cheung Chun-yuen tells Post Leung "may have remembered incorrectly" details about the trellises. Ho files election petition to challenge ballot result.
July 13 Executive councillor Fanny Law Fan Chiu-fun tells Post Leung had not double-checked records before answering reporters. Law learns from his wife that wooden trellis was built by their family.
July 16 Leung refuses to comment on trellises in his first Legco meeting due to legal proceedings.
July 30 Court of First instance rejects judicial review.
September 12 High Court says judicial review can proceed.
October 5 High Court dismisses Ho's election petition.
November 13 Court of Final Appeal rejects Ho's appeal.
November 19 Ho withdraws legal challenge formally.
November 23 Leung claims memory was wrong.