Alun Cairns resigned as Welsh secretary on 6 November over claims he knew about a former aide's role in the "sabotage" of a rape trial.
Here is a timeline of key events that led up to him resigning from the cabinet.
April 2018: Ross England, who previously worked in Alun Cairn's Vale of Glamorgan constituency office, gives evidence in a rape trial. The defendant, James Hackett, is a friend of Mr England.
Judge Stephen John Hopkins QC had earlier made clear evidence of the sexual history of the complainant was inadmissible. Mr England claims in his evidence that he had a casual sexual relationship with the complainant, which she denies. The trial collapses. The judge tells Mr England: "You have managed singlehanded, and I have no doubt it was deliberate on your part, to sabotage this trial."
July: At a retrial Hackett is convicted of rape.
August: An email is sent to Alun Cairns by Geraint Evans, his special adviser. It is copied to Richard Minshull - the director of the Welsh Conservatives - and another member of staff.
It says: "I have spoken to Ross and he is confident no action will be taken by the court."
December 2018: Ross England is chosen to be the Conservative candidate for the Vale of Glamorgan at the 2021 Welsh Assembly election. Alun Cairns endorses Mr England as a "friend and colleague" with whom "it will be a pleasure to campaign".
29 October 2019: The victim of the collapsed trial tells BBC Wales: "For them to make him a candidate in their target seat for the Welsh assembly proves how little respect they have for me, how little respect they have for the criminal justice system."
Mr England says in a statement: "I gave an honest answer."
30 October: Ross England is suspended as a Conservative candidate. At Prime Minister's Questions, Boris Johnson refuses to be drawn on whether Mr England should no longer by a Tory assembly candidate.
31 October: Welsh Tory party chairman Lord Davies of Gower issues two statements. In the first he says: "We were fully aware that Ross England was involved as a witness in a sensitive case" and goes on to say an investigation into Mr England is under way.
In the second he says he could "categorically state" both he and Mr Cairns were "completely unaware of the details of the collapse of this trial until they became public this week".
5 November: The August 2018 email sent to Alun Cairns comes to light. The rape victim calls on Alun Cairns to resign.
A Welsh Conservative source tells the BBC: "I can't really see how he can possibly carry on - the toxic nature of these revelations could bring down the whole Conservative [general election] campaign in Wales."
6 November: Alun Cairns resigns as Welsh secretary. In his resignation letter he says: "I will co-operate in full with the investigation under the ministerial code which will now take place and I am confident I will be cleared of any breach or wrong doing."
Mr Cairns intends standing again at December's general election but a Welsh Conservative source questions whether he should, saying: "If you can't hold the line as a cabinet minister, how could you credibly be a candidate?"
The Conservative leader in Cardiff Bay, Paul Davies, distances himself from Ross England, saying he has "fallen short" of the standards required of a Tory Welsh assembly candidate.
7 November: The victim in the collapsed rape trial tells BBC Wales the case shows why women do not alert police when they are attacked.
Asked on BBC Radio Wales Breakfast to apologise for the way the Conservative Party has handled matters, Welsh Tory chairman Lord Davies of Gower says he "deeply regrets" that the situation has arisen but adds: "There will be an apology if I find out that one should be forthcoming."
In the interview, Lord Davies also contradicts one of his statements from 31 October when he insists multiple times that he did not know Ross England was a witness in the rape trial.