A Cabinet Office investigation into former Welsh secretary Alun Cairns' knowledge of a collapsed rape trial has been branded a "sham" by the female victim.

The MP for the Vale of Glamorgan stepped down from the Cabinet after it was revealed that he had endorsed a Welsh Assembly candidate accused by a judge of sabotaging the trial.

Mr Cairns claimed he was unaware of the role played by Ross England in the collapse of the court case until after the story broke in October, but a leaked email suggested he had been made aware of the allegations earlier.

A Cabinet Office investigation found Mr Cairns had not breached the ministerial code, but said it was "unlikely" that the MP was not told anything about his former staff member's role.

The rape victim, another of Mr Cairns' former staff members, told BBC Two's Victoria Derbyshire programme on Thursday that she was not contacted by the investigation and claimed it had been merely a "deflection" until after the general election.

The woman, who cannot be named, said: "The whole thing feels like a sham. What kind of investigation doesn't contact the person who is most affected?

"It makes me question how seriously it was actually carried out. This was a deflection until after the general election, not a genuine investigation into Alun's truthfulness."

She added: "I would've hoped Alun would've used the inquiry as an opportunity to be honest, and it's regretful that he did not. Fortunately nobody with an ounce of common sense believes this ludicrous claim that he did not know."

The woman claimed Mr Cairns told her "I think you're being a bit harsh" in pursuing the rape complaint against Mr England's friend, James Hackett, who was eventually found guilty of rape and jailed.

She also said she was subjected to a "smear campaign" by individuals inside the party who accused her of being a liar.

The Cabinet Office report by Sir Alex Allan, the Prime Minister's independent adviser on ministers' interests, stated that Mr Cairns said he knew about the collapse of the trial, but did not know the details until they become public.

It concluded with Sir Alex writing: "I find it unlikely that Mr Cairns would not have been told something about Mr England's role when he was told about the collapse.

"But all those involved state that they had not informed Mr Cairns of Mr England's role, and there is no direct evidence to contradict this. On that basis, I do not find that the evidence upholds the allegations of a breach of the ministerial code."

Mr Cairns was replaced as Welsh secretary by Simon Hart following the Conservatives' election victory on December 12.

A Welsh Conservative Party spokesman said: "We are deeply sorry for the circumstances surrounding the collapse of the trial and the deep distress this must have caused the victim, her family and friends.

"Mr England has been suspended and a full investigation is under way."

A Cabinet Office spokesperson said: "We have every sympathy with the individual in this case. The investigation specifically looked at whether Mr Cairns' statement was true and therefore whether or not he breached the Ministerial Code.

"In light of this and the individual's anonymity, it was not considered appropriate or necessary to contact her."

Mr Cairns has been approached for comment.