A senior Welsh Tory official has quit, calling for party chairman Byron Davies to resign, accusing him of "complete inaction" on "serious matters".
Lee Canning, who was a deputy party chairman, also said ex-Welsh Secretary Alun Cairns should "maybe have stood aside" as a general election candidate.
Mr Cairns quit the cabinet after it emerged he was told about an ex-aide's role in a rape trial's collapse.
Lord Davies called Mr Canning a "disgruntled failed" Tory candidate.
Mr Canning resigned to join the Abolish the Welsh Assembly Party on Monday.
In his resignation letter, Mr Canning said the "complete inaction by our party chairman on serious matters" had left him with "no option" but to resign with immediate effect.
It follows the revelation that Ross England, a former aide to the Welsh secretary and Conservative candidate for the next assembly election, had been accused by a judge of deliberately sabotaging a rape trial in April 2018.
The defendant, James Hackett, was convicted at a subsequent trial.
Having claimed that he did not know about Mr England's involvement until the story broke, Mr Cairns resigned as Welsh secretary after it emerged he had been sent an email about the case in August 2018.
The matter is now the subject of a Cabinet Office inquiry, under the Ministerial Code, and Mr Cairns says he is confident he will be he will be cleared of any breach or wrong doing.
Lord Davies maintains he did not know about the circumstances around the collapse of the trial until Hackett's appeal ended on 15 October.
However Mr Canning told BBC Wales on Tuesday he does not think "there's any way that he wouldn't have known about it", as party chairman.
Mr Canning also claimed to have tried to raise the Ross England issue during a meeting at the Conservative Party conference at the beginning of October and at a subsequent Welsh Conservatives board meeting in Lampeter on 8 November, but said that he was "shot down".
"I don't have any hard physical evidence that he's been told from anyone else but I was told whenever I brought it up to not bring it up again otherwise there's going to be trouble," he said.
Asked if Mr Cairns should have stood down as a candidate for the general election, Mr Canning said: "I think that Alun should maybe have stood aside in this one.
"It would have been better for him and it would have been better for the party, particularly with this case, and if he'd stood aside it would have given him the opportunity to defend himself."
Mr Canning had sought selection as a candidate for the Conservative Party but said he was "blackballed" and prevented from standing due to what he claimed was a "joking" tweet he sent in 2012.
In the tweet, he said, he had called a female friend a "slag".
However other candidates have done "much worse", he told the BBC.
Mr Canning said he had "serious concerns" about the management of the Welsh Conservatives.
"I do want to reiterate that I do have a lot of friends in the party that put in a tremendous amount of hard work but there's issues there that do need to be remedied and I think the best way for them to be remedied would be for Byron to stand down."
Responding to Mr Canning's claims, Lord Davies said: "Lee Canning is a disgruntled failed Conservative candidate, and I am saddened that he has taken to the media to vent his frustration.
"At no time did Lee Canning try to raise the Ross England issue with me as quoted.
"As has been widely reported, the matter is now the subject of a full investigation and we will not be commenting further on it."