The PSNI is probing a claim by NI21 leader Basil McCrea that he has been the victim of a conspiracy to destroy his political career.
he Lagan Valley MLA fought a two-year campaign to clear his name after a young party worker made claims of sexual misconduct against him.
He was also accused of taking "voyeuristic" photographs of another young woman and touching her inappropriately.
The Belfast Telegraph has obtained access to a report by the Assembly watchdog Douglas Bain clearing Mr McCrea of wrongdoing. It is due to be published later this week.
In an exclusive interview, Mr McCrea (56) revealed he had suffered post-traumatic stress disorder and diabetes as a result of the pressure he has been under since the allegations surfaced before the European election in May 2014.
"What happened to me should not have happened to anybody," Mr McCrea said.
"I'm not crawling away. I'm speaking out to show the sordid side of Northern Ireland politics."
Mr McCrea said he was pleased to have been "completely exonerated" by Douglas Bain's report, but that the delay in its publication had taken its toll on his "health, relationships and political opportunity".
He intends to defend his Lagan Valley seat in this May's Assembly election.
"I'm going to stand for NI21 (as) the only candidate," Mr McCrea said.
"My number one objective is to clear my name, to expose those who have done this to the party. I hope I'm able to contribute to changing the political environment in the future."
In a lengthy interview, an angry and sometimes emotional Mr McCrea described the allegations against him as "horrendous".
The Stormont report details a lurid account by Ashleigh Murray, a 23-year-old former NI21 volunteer who later worked as a party employee, claiming that in April 2013 Mr McCrea approached her in his hotel room with his trousers down and genitals "on display", and pulled down her tights.
Ms Murray also claimed that on other occasions he had touched her legs and bottom and had made "sexual comments". Mr McCrea vehemently denied the allegations and the Standards Commissioner Douglas Bain found his evidence "credible".
The MLA said the claims affected him deeply. "I couldn't read them for ages," he added.
"It still upsets me to read them now. It brings it all back. I'm a human being and it hurts."
He stressed that Ms Murray's claims were never reported to the police and that officers had never interviewed him about that or any other matter.
The PSNI confirmed that no such reports were received.
Mr McCrea said he was also hurt and angry that pictures he took of another young party worker were, according to the Standards Commissioner, "heavily doctored" to make them appear improper.
The same woman also accused him of touching her bottom during an NI21 trip to Cork.
Mr McCrea said that these "entirely unfounded" complaints about sexual impropriety had affected him deeply and had made him almost paranoid about his dealings with colleagues and the general public.
"I go nowhere now unless I have someone I trust with me, so there's no misunderstandings," he added.
"The campaign against me is ongoing and relentless. I'm aware that in recent times people are still trying to make insinuations or allegations.
"I'm hypersensitive to how things look. You become acutely aware of people. I'm extremely cautious. I never meet anyone alone, men or women. It's easier for me now to have a second opinion, as a witness."
Mr McCrea said that the intense stress he had experienced since the emergence of the allegations and during the Bain inquiry had contributed to serious ill health.
"The stress levels were huge," he told this newspaper. "I battled my way through it, but it took huge resilience to do so.
"I think I had post-traumatic stress disorder. I was diagnosed with type 2 diabetes in August 2015, almost certainly brought on early by the stress. There are ongoing medical complications.
"But I am exercising more - lots of cycling - and I have lost one and a half stone. I am healthier now than I have ever been. It was a wake-up call."
The impact on his family - his partner Jill, adult children and grandchildren - also left him frustrated and upset.
"They have been universally supportive and tremendous, but they have suffered distress," Mr McCrea said.
"People have said unkind things to my nieces, cruel comments. My family always believed in me. They think a grave injustice has been done, and their only thought has been for my wellbeing."
What of his former partner in politics, John McCallister?
"I thought my politics was the same as his politics," said the Lagan Valley MLA.
"We got on well personally, but he preferred to get others to do the work and he would do the presentations.
"And John became increasingly strident about being a unionist. It was getting fractious. He felt that he should be the European candidate, rather than Tina McKenzie."
Their relationship ended in spectacular and very public fashion on the eve of the European elections in May 2014, when Mr McCallister branded the party "dysfunctional" in a media interview. The election turned out to be a disaster for NI21.
"I turned up at the European count, which no one expected," Mr McCrea said. "What should have been a triumph for us was actually an appalling vista. I went there because of the candidates. They were angry with the party. I was not hiding away. I had been accused in the wrong. There had been headlines in the Press that were unfounded and malicious.
"I have always been a fighter. I have never run away. There was a determination in me not to let the people who did this to me get away with it. On many occasions, people have said to me that it is finished and I should walk away.
"The reason why I don't do that is that if I don't stand my ground, no one new will ever enter politics."