As reported by The Guardian 1st December 2017 Mr Green was investigated by the Cabinet Secretary about an accusation of inappropriate behaviour towards a young Conservative activist, Kate Maltby.
The published summary of the Cabinet Secretary's report states that it was not possible to reach a definitive conclusion on the appropriateness of Mr Green’s behaviour with Kate Maltby in early 2015, though the investigation found Ms Maltby’s account to be plausible. In his letter to the Prime Minister, Mr Green states that he "deeply regrets the distress caused to Kate Maltby following her article about me and the reaction to it. I do not recognise the events she described in her article, but I clearly made her feel uncomfortable and for this I apologise."
Separately, two former senior Scotland Yard officers claimed that pornography was found on Mr Green's office computer when he was in opposition. The discovery was made in 2008 when Mr Green was shadow immigration minister as part of Operation Miser, an investigation into Home Office leaks. Mr Green strenuously denied accessing pornography on his work computer.
The summary of the Cabinet Secretary's report states that: - Mr Green’s statements of 4 and 11 November, which suggested that he was not aware that indecent material was found on parliamentary computers in his office, were inaccurate and misleading, as the Metropolitan Police Service had previously informed him of the existence of this material. These statements therefore fall short of the honesty requirement of the Seven Principles of Public Life and constitute breaches of the Ministerial Code. Mr Green accepts this." [Links added].
The consequence was that the Prime Minister asked Mr Green to resign from the government due to his breaches of the Ministerial Code. He was removed because he had denied being told that pornographic material had been found on his parliamentary computer - BBC News 5th November. Also see BBC Damian Green - Timeline of his downfall where, against 11th November 2017, it is said - "Former Metropolitan Police commissioner Sir Paul Stephenson says he had been aware of allegations about pornography being found on Mr Green's office computer. Mr Green says: "I reiterate that no allegations about the presence of improper material on my parliamentary computers have ever been put to me or to the parliamentary authorities by the police. I can only assume that they are being made now, nine years later, for ulterior motives."
The Seven Principles of Public Life were set out in the Nolan Committee's First Report on Standards in Public Life - 1995 issued by the Committee on Standards in Public Life chaired by Lord Nolan.
The Ministerial Code has its origins in written guidance for Ministers issued in the 1980s. The first document to be entitled Ministerial Code dates from 1997 and the most recent version was released in December 2016.
Annex A to the latest Ministerial Code (pdf) incorporates the Seven Principles of Public Life.
The Independent 20th December
HM Inspector of Constabulary - Report - Operation Miser
Previous post 2nd December
Update 21st December:
Metropolitan Police Statement - reference to Information Commissioner