Bob Chappell disappeared from the yacht. Meaghan Vass's DNA was found on the Four Winds, but in court she swore she had never boarded the boat. Mr Richter's white paper suggests Chappell was killed when he disturbed Vass and other vagrants, who had boarded the Four Winds planning to steal from it. The dossier names two men with extensive criminal records who may be involved in the murder. Neill-Fraser has maintained her innocence, but was convicted by a jury in 2010, a finding later upheld on appeal. It is the biggest legal story in Tasmania. And Richter, an intense, bearded QC regarded as one of Australia's finest and most forensic trial advocates, had travelled to Hobart to tell the Premier that police may have got it terribly wrong.

Lawyer Robert Richter outside court in September last year. Credit:Jason South The 25-page white paper contained an extract from a secret statutory declaration made by Vass a week earlier in which she admitted to being on the yacht the night Chappell disappeared. Along with other information detailed in the white paper, Richter believed Hodgman would be forced to consider an independent inquiry. The yacht Four Winds was moored off Hobart in 2009. Despite years of intense media scrutiny of the case, the contents of the white paper have been a tightly held secret. Richter requested that Hodgman and the others in the room – Tasmania's acting attorney-general Matthew Groom and the solicitor-general Michael O'Farrell SC – not pass it to the Tasmanian police.

Hodgman and Groom declined to read the white paper but agreed that O'Farrell should review it. Richter flew back to Melbourne and waited for a reaction. Sue Neill-Fraser and Bob Chappell. It came this month, although not in the manner Richter expected. Witnesses named in the white paper who helped compile or corroborate aspects of Vass's statement – her associate Karen Keefe, a lawyer Jeff Thompson, and another man who must remain anonymous, Witness X – have all been arrested by Tasmanian police and charged with perverting the course of justice. Former police officer Colin McLaren. Credit:Jason South

The police allege they have concocted or coerced evidence to clear Neill-Fraser and support Vass's statutory declaration. The arrests have plunged the small state's criminal justice system into the spotlight and led to claim and counterclaim of cover-ups and witness intimidation. Sue Neill-Fraser on Australia Day 2009. A compelling case The possibility of strong-arm tactics by the police were flagged in the white paper given to Hodgman in May.

Witness X is recorded in the white paper as claiming he had been visited in jail by detectives and warned he may be charged if he co-operated with Neill-Fraser's legal team. But police insist they have acted appropriately, accusing Neill-Fraser's supporters of dirty or illegal tactics. The case that sent Neill-Fraser to jail was circumstantial but compelling, due largely to a series of jarring lies she told police about her activities at the time of Chappell's disappearance. Neill-Fraser has continued to protest her innocence, dividing the Tasmanian community and the mainland media. Her supporters have paid for a billboard in Hobart promising a $40,000 reward for "true facts leading to the release of Sue Neill-Fraser". The confidential dossier presented to Hodgman outlined evidence that could do just that.

Meaghan Vass' DNA was found on the Four Winds yacht. Credit:Facebook In her signed statutory declaration, Meaghan Vass – who in 2009 was a homeless 15-year-old who hung out with criminals – answers a question that for years confounded police, prosecutors and defence lawyers; how did her DNA get on the deck of the Four Winds? Vass testified at the original murder trial that she had never set foot on the yacht and had nothing to do with the events of January 26, 2009. Police suggested that her DNA may have arrived via secondary transfer: on the boot of a police officer or crime scene examiner. But in her brief statutory declaration, signed on April 27, Vass says she was on the yacht on the night in question.

The white paper and the statement by Vass, now 23 and still enmeshed in Tasmania's criminal underworld, have never before been made public, but both have been sighted by Fairfax Media. Vass seeks an indemnity from prosecution and states that she "was on the Four Winds yacht on the night of Australia Day 2009 with other people". She also states that she is "scared", that "nobody understands my grief" and that "Sue Neill-Fraser was not on the yacht". The contents of the white paper also make clear that Vass is a difficult, unreliable witness. If Neill-Fraser and Chappell are representative of those with means in Tasmania, Vass is a small cog in the state's underbelly, a seedy milieu of substance-abusing criminals.

Vass was tracked down in Tasmania by a former Victorian senior sergeant, Colin McLaren, who also attended the meeting with the premier. Both McLaren and Richter are working on the Neill-Fraser case pro bono. As an undercover operative, McLaren famously infiltrated Australia's most powerful Calabrian mafia cell in the 1990s. To convince Vass to talk, McLaren had to deal with an outlaw bikie club, the Devil's Henchmen. Depending on who you ask, Vass has gone into hiding in the club, protected by its president and her boyfriend, "Sharkie". Others suggest the club may be less a sanctuary for Vass than it seems. The white paper, which was compiled by McLaren for Richter, details a phone conversation in January between McLaren, Vass and a female "hanger on" of the Devil's Henchmen, Karen Keefe.

Keefe facilitated contact between McLaren and Vass after meeting Neill-Fraser in Risdon prison. "What do I say," Vass asks Keefe, according to McLaren's record of the conversation in the white paper. "Tell them what you said to me," Keefe tells Vass. "I was on the yacht with [two criminals]," Vass replies. "And?" Keefe prompts.

"And there was a fight?" Vass states. In an earlier conversation facilitated by Keefe, Vass told McLaren about attending a party with two criminals on a yacht moored near the Four Winds. "We were there on the yacht partying. I can't remember but I have to think about it," Vass purportedly said, before claiming the trio had used a dinghy to board the Four Winds. "There was a fight on the other yacht … the old guy's yacht," Vass told McLaren, according to the white paper. The white paper also includes extracts from statements Keefe and Witness X (who can't be named as he is facing trial for other charges).

They partly corroborate the theory that Vass was on, or in the vicinity of, the Four Winds and in the company of at least one violent criminal, on the night of the murder. Witness X, who has never met Keefe or Neill-Fraser, claims he saw Vass on the night of the 26th in the company of a man called "Sam" near the beach where the Four Winds was docked. The pair "discussed breaking into yachts". Vass and Keefe have also been video recorded discussing elements of the case. These recordings were organised by Eve Ash, who accompanied Richter and McLaren to the meeting with Hodgman. Ash is a film-maker, and a friend and campaigner for Neill-Fraser. She is making a documentary about the case with leading Australian television production firm CJZ and has filmed Vass in a hotel room.

On this video recording, an agitated and seemingly scared Vass refuses to talk about the night of the 26th, but says that she thinks about Neill-Fraser "every day". Independent inquiry Despite their obvious credibility problems and the fact their statements have not been verified in any forensic setting, Vass, Witness X and Keefe's comments, combined with the fact of Vass's DNA on the deck of the Four Winds, were enough for Richter to urge the Premier to commission an independent inquiry. Such an inquiry could have the ability to compel witnesses, including Vass, to testify about what they knew about the case. It could also examine allegations made by Witness X that he was told by detectives he would be charged with historic offences if he co-operated with Neill-Fraser's legal team.

While Richter's team also hopes the evidence in the white paper may form the foundation of Neill-Fraser's last-ditch legal appeal in the Supreme Court (the appeal has been adjourned indefinitely but could be held as early as October), an inquiry would be able to find and test the white paper evidence in a manner unconstrained by court procedure. The Tasmanian police, though, had other ideas. At the start of August, Keefe was charged by Hobart detectives with perverting the course of justice over allegations she had been offered an inducement by an unnamed party to lie about Vass and compel the younger woman to testify falsely in Neill-Fraser's appeal. Keefe is accused of agreeing to receive $3000 in cash, a $40,000 reward and a further $50,000 in the form of an "education fund" for herself and her children. Tasmanian detective Shane Sinnitt, who played a lead role in the original Neill-Fraser investigation, also helped police charge Tasmanian solicitor Jeff Thompson, who is working with McLaren on the case.

Thompson's charges stem from a visit he paid to Witness X in jail as he sought to confirm Witness X's claim he had spoken with Vass and her male companion, "Sam," on the night of January 26, 2009. Under the glare of prison security cameras and guards, Thompson showed Witness X a photoboard created by McLaren and depicting Sam and seven men who resemble him. In charging Thompson, Detective Sinnitt accuses the solicitor of "influencing" Witness X to select the photo of Sam. Back in 2010, Sinnitt unsuccessfully sought to confirm Vass' whereabouts on the the night of the January 26. Sinnitt's own files reveal he was told in 2010 by a witness that Vass had failed to return to her usual accommodation that night and may have been in the company of a man called "Sam."

(In a statement, Tasmania Police say Sinnitt was "seconded" to the team investigating the allegations against Thompson and Keefe "to utilise his detailed knowledge of the evidence gathered in the [original] murder investigation"). Tasmania Police also charged Witness X with perverting the course of justice in connection to his claims about the Neill-Fraser case. After charging Thompson, Keefe and Witness X, Tasmanian detectives contacted television production company CJZ, demanding last week that it hand over the video recordings of Keefe, Vas and McLaren. Series of arrests The police activity in the past month suggests the potential evidence Richter hoped would prompt Hodgman into action has instead been used by Tasmanian detectives to make a series of arrests.

According to a source working with Richter, rather than being used to outline a case to clear Neill-Fraser, the contents of the white paper has instead been used to demolish it. In a statement, Assistant Commissioner Glenn Frame says a "complex investigation" that began in February led to the charging of "three people who we allege intended to fabricate evidence in support of the Supreme Court appeal of Susan Neill-Fraser". Frame also indicates "the material contained in the white paper" is central to the charges against Witness X, Keefe and Thompson. But because "the matters are before the court," Frame says he can't provide further details. Frame does, however, flag "the possibility of further charges." Both Colin McLaren and Eve Ash have told friends they anticipate being raided or arrested.

Assistant Commissioner Frame also says that the white paper has not been provided by Sue Neill-Fraser's legal team "directly" to Tasmania Police but that a team of detectives with no connection to the original murder probe have investigated "material provided to the DPP." That material is Vass' statutory declaration. Privately, police insist that the white paper is largely debunked by earlier police investigations. The two criminals (including Sam) named as Vass' associates and possible murder suspects have previously been interviewed, with police finding no evidence to tie them to any foul play. But the fight over the white paper may only be starting.

Sources have told Fairfax Media that on Wednesday, two other members of Neill-Fraser's legal team, respected criminal defence lawyer Paul Galbally and Tom Percy QC, may flag with the Tasmanian Supreme Court the question of whether police or senior Tasmanian officials are in contempt of court by authorising the charging of the white paper witnesses. Neill-Fraser's appeal is set down for a mention in Hobart. Barrister and Australian Lawyers Alliance spokesman Greg Barns, who practices in Melbourne and Hobart and gave some early advice to Neill-Fraser in 2009, says Tasmania's criminal justice system is itself on trial. "The test of the robustness and integrity of any justice system, including that of Tasmania, is how it deals with hard cases such as those in which it is alleged there has been a wrongful conviction," he says. Got a tip for Fairfax Media's investigative team? Contact us via our secure, confidential and anonymous tip-off portal.