At a hearing before a special Legislative Council committee yesterday, Lam Woon-kwong, the Secretary for the Civil Service, ended an official silence and claimed that Mr Leung had to go because he was guilty of serious financial irregularities.
Mr Lam also added a new term to the lexicon of official mendacity by admitting that his previous statements, alleging that Mr Leung had resigned for "personal reasons", amounted to a "narrow interpretation of the truth". He was also forced to admit that he had withheld documents from the legislative inquiry.
Mr Lam tried to persuade the inquiry that the reasons for Mr Leung's departure related to his failure to disclose a number of business interests. He is alleged to have formed an advertising company in China while heading a department "dealing with a lot of immigration matters with China". He also, allegedly, failed to disclose holdings in a company with assets of some pounds 25m, and in another owned jointly with a prominent pro-Peking legislator.
Mr Leung's business interests and alleged failure to repay a government housing loan were unearthed during a corruption inquiry and in an integrity vetting investigation by the police - which he failed to pass.
Invited to categorically deny that there had been political motives behind the government's loss of trust in Mr Leung, Mr Lam oscillated between denying reports in The Independent and other British newspapers, and saying he had no personal knowledge of these matters, leaving it open to question whether others, including Mr Patten, were aware of investigations into Mr Leung.
However Mr Lam claimed that the "security and integrity" of the immigration department was "not compromised, as far as we know". Allegations have been made that Mr Leung disclosed names of people holding British passports issued under the secret British Nationality Scheme which allows certain key job-holders to gain British citizenship in Hong Kong. China fiercely opposes the scheme and is keen to know who has benefited from it.
Legislators were concerned by the gaping holes in Mr Lam's version of events. He failed, for example, to explain why it took the government more than two months to act after the end of the investigation and why, when it did, it became so urgent for Mr Leung to leave office within hours.