The ex-lover who helped bring down disgraced FBI spy Charles McGonigal took her own life - despite friends and family insisting they could not believe she would die by suicide, the Daily Mail can exclusively reveal.

Allison Guerriero, 52, was found dead inside her rented apartment in Boynton Beach, Florida, on August 27 - triggering weeks of speculation over the mysterious circumstances surrounding her death. 

The former security consultant died hours after sharing a series of posts on X, including a video of herself walking in the street demanding a spotlight on other Feds and another where she declared: 'I hate the FBI.'

But the Daily Mail can now reveal Guerriero's death was determined to be a suicide.

The revelation comes after the Palm Beach County Medical Examiner denied the Daily Mail's request for an autopsy report, citing a Florida law protecting the privacy of suicide victims and their families by exempting the reports from public record requests.

A source close to the investigation later confirmed to the Daily Mail that suicide was the cause of death, but gave no further details. 

Guerriero infamously had an 18-month affair with disgraced FBI counter intelligence chief McGonigal that later helped blow the lid on his crimes, which included secretly working for Russian oligarch Oleg Deripaska who has close ties to Vladimir Putin.

Her death on August 27 came a day after security consultant Jackie Singh published a lengthy article on website Hacking, but Legal that was highly critical of her.

In particular, it picked apart her life, certain actions she took over 58-year-old McGonigal and her involvement with other well-known figures.

However, after her body was found around 8pm, family and close friends insisted to the Daily Mail that cancer survivor Guerriero would never kill herself and instead suspected possible foul play or an accident.

Among them was her 80-year-old father Bill, who indicated he was in the dark by telling the Daily Mail Friday that he has not seen the autopsy results, but 'I would like to know what they have to say.'

Close friend Roger Stone, the high-profile Florida conservative lobbyist and close ally of President Trump, was shocked when told of the latest tragic twist.

'Based on my communications with her on the day before and the day of her passing and her devout Catholicism I still have a hard time believing that she took her own life,' he said.

Stone, who also hosts a podcast offering insider political analysis, had hired a private investigator to look into the death. Guerriero was researching for him before she died.

He added: 'It's impossible for a private investigator to reach an alternative conclusion from the state without access to the evidence, medical records, or autopsy. It is of course, possible that her death was accidental.

'At this point, her family deserves privacy, and I intend to comment no further. She was a great and talented friend. 

'Characterizing her as a "mistress" is, I believe, unfair in that I believe McGonigal misled her about the status of his marriage. May she now rest in peace.'

Immediately after her death, he told the Daily Mail: 'I heard from her by text on the day she passed away and she seemed in excellent spirits. They were work related.

'Allison was a brilliant researcher and writer with an excellent knowledge of both law enforcement and our intelligence capabilities and wide network of contacts. She was widely respected in that world.'

Meanwhile, security consultant Singh said after being told the latest news: 'I am saddened to learn that Ms Guerriero may have taken her own life in the wake of my story about her statements and background.'

Immediately after the death, she had said: 'What I saw was a person who was highly destabilized by the notion that I was going to drop this piece. But I'm disturbed right now.

'Did somebody whack her? I don't think so. I think most likely she whacked herself. Oh man.'

Guerriero and Singh had been in contact leading up to publication, with the former sending three text messages on the day she died.

Part of the final one read obliquely: 'I don't wanna wreck your life like they did to me.'

Guerriero's death certificate, obtained by the Daily Mail, does not reveal the cause of death because it is the short form version available to the public. 

In Florida, longer versions available to family do reveal that information.

Her passing came hours after she shared a flurry of 75 posts on X, including a video of herself walking in the street demanding a spotlight on other Feds and another where she declared: 'I hate the FBI.'

They were part of her unrelenting years-long campaign often conducted on social media against married McGonigal and her personal war against other senior figures in the agency.

She was also clearly aware of the dangers of crossing swords with Moscow after the link to one of President Putin's cronies was revealed.

Her inner thoughts were revealed in text messages with independent researcher Anthony Gonzales, who posts information under the name Anthony Andrews. They were disclosed in Singh's piece.

Gonzales asked her about reprisals and she replied: 'As if I don't have the same concerns? I turned in a traitor working for the Russians.

'They don't scare me. If they wanted me dead I'd be dead five or six years ago. I'm assuming they have wires up on my comms as well as Albania, Bosnia, Croatia, Serbia etc...

'And definitely Mexico and Colombia because of past drug trafficking investigations I was a contractor on.'

Guerriero said in another text to Gonzales: 'I work with the military, law enforcement and the intelligence community. We always say 'nobody would even believe us if we told them these stories'.'

And she claimed regarding McGonigal's downfall: 'But I did pick up a lot of trade habits that enabled me to know how to collect the right evidence on Charlie. And it was hard.'

McGonigal is serving six years in federal prison but Guerriero always believed he should have received a harsher sentence, telling the Daily Mail in 2024: 'He's a traitor.'

On the day of her death, she posted a selfie video of her strolling in Boynton Beach saying: 'Hey, good morning everybody. Friends and enemies… of course I'm in the middle of all my PTSD from 9/11 but I'm actually breathing a huge sigh of relief…

'Here's the problem with Charles McGonigal. You know his name, but you never did before that. You knew Jim Comey's name. You knew Chris Wray's name.. all the names that you already know, you know. Why don't you start looking for the names that you do not know?'

Guerriero was a former vice president of US operations for Israeli security firm Mifram while working in New York. She first met McGonigal in spring 2017 as a volunteer for the Federal Enforcement Homeland Security Foundation charity.

The then $200,000-a-year Fed wooed her over dinner, claiming he was going through a divorce from wife Pamela who he called 'a nag' who never agreed to sex.

His family home was in Chevy Chase, Maryland, but he lived in a sublet apartment in Park Slope, Brooklyn following his 2016 New York appointment by then-FBI director Comey.

In the three years before her death, Guerriero was exclusively interviewed several times by the Daily Mail, spilling on the couple's sex life and McGonigal's treachery.

While they were living together in his Brooklyn apartment, McGonigal flaunted his relationship with Guerriero, taking her into the FBI's main office in Manhattan and up to what she calls the 'Kings of New York' floor – introducing her as his 'girlfriend.'

He cleverly masked signs of his overall treachery, passing off any outward clues as part of his role. 

He took a trip to Albania during their relationship in 2017 and at one point asked Guerriero to accompany him to meet sanctioned metals magnate Deripaska.

According to court papers, on October 5 McGonigal received $80,000 from his former Albanian intelligence official associate in a car parked outside a New York restaurant.

Weeks later, Guerriero made a startling discovery in their apartment. A bag containing what she now knows was $80,000 in $100 bills, neatly rolled.

'My mind went to them being what we call flash rolls, money you would give an undercover informant or an undercover agent for them to continue operating in the field,' she told the Daily Mail.

Challenged, McGonigal claimed he had won the money betting on a baseball game. Guerriero listened patiently but was suspicious.

However, it was McGonigal's confession that he was not divorcing his wife that led to their breakup on Christmas Eve, 2018 – three months after he retired from the FBI and later became an $850,000-a-year head of security for a bank.

Guerriero tipped off people she knew at the FBI about her suspicions in 2019 after reflecting on events. 

Her accusations appeared to have fallen on deaf ears, although the wheels of justice obviously did begin to turn on McGonigal and he was arrested in January 2023.

'After Charlie and I had broken up, I had spent a series of weeks and months rolling everything over in my head,' she said. 

'And it had occurred to me, this guy's a traitor. Every time I tried to talk to the FBI about it, they didn't want to listen.'