In letters to the Independent Police Complaints Commission, Police and Crime Commissioner Matthew Ellis questioned the ‘evidence’, ‘objectivity’ and ‘balance’ of the lengthy probe into failings by Staffordshire detectives and senior officers investigating the 2002 gangland killing.

WATCH: The Kevin Nunes Staffordshire Police scandal explained

Mr Ellis cleared then-Staffordshire Chief Constable Jane Sawyers of any wrongdoing over mishandling the Nunes case in 2015, rejecting the IPCC's findings she should be disciplined for gross misconduct.

He published the correspondence with the watchdog, dated March and June 2015, after growing increasingly frustrated over delays by the body in releasing its full report over the affair, known as Operation Kalmia.

In the letter to IPCC Commissioner Cindy Butts, Mr Ellis said: “I do not think that the report is always objective or evidence-based in reaching its conclusions or consistently provides an accurate summary of the extensive evidence. The report also does not provide a balanced commentary and omits important considerations and analysis.”

He adds: “Operation Kalmia consistently presents a view that Mrs Sawyers was unimpressive in carrying out her roles and responsibilities and in part and at specific times, I agree with this analysis. However, I do not consider that there is evidence of an officer who was unwilling or unable to discharge her duties or was eager to evade responsibility and accountability, as portrayed within the investigation report. The report is in parts pejorative, unreasonable in its analysis and its conclusions are too often at odds with the investigation report and the supporting evidence provided.”

A top criminal lawyer and police ethics chief advised Mr Ellis over his decision to reject the IPCC's findings.

Mrs Sawyers faced five allegations over failing to properly handle and disclose a damning internal report into the unit handling the Nunes case. She was one of 14 Staffordshire officers investigated. She says the IPCC report is 'flawed'.

Stafford Rangers footballer Kevin Nunes, from Whitmore Reans in Wolverhampton, was killed in an ‘execution-style’ shooting in a country lane in Pattingham in September 2002.

• MORE: How Kevin Nunes' murder became major Staffordshire Police scandal

Five Black Country gangsters were jailed over the murder in 2008 but four years later had their convictions quashed after a series of failings and wrongdoing by detectives were exposed by a whistleblower.

Ex-Derbyshire Chief Constable Mick Creedon, who carried out the IPCC probe, said: "‘I look forward to the publication of the report. I stand by it. The tragedy here is that no one has been held to account for the murder of a young man. For the Nunes family, there can be no closure."

Police chief takes stand on report delay

A police chief has said he is 'dumbfounded' by repeated delays by the force watchdog in publishing its long-awaited report into the Kevin Nunes murder scandal.

Matthew Ellis, the Staffordshire Police and Crime Commissioner, today published two letters from 2015 which explain why he cleared ex-Chief Constable Jane Sawyers of any wrongdoing and which appear to discredit the Independent Police Complaints Commission's Operation Kalmia report.

It is nearly three years since the investigation into 14 Staffordshire detectives and senior officers - including three Chief Constables and an Assistant Chief Constable - was completed by the IPCC. But its full report has yet to be published with repeatedly missed deadlines.

If the 566-page Operation Kalmia report is released it is expected to be heavily censored.

Mr Ellis said: “It has cost the public purse many millions of pounds and despite that, and the time taken, nobody is being held to account for historic failures. The principle of justice has not been well served and the system is poorer for it.

“My decision to make public now the papers and correspondence I own the copyright to, is broadly frustration and my determination to practice what I have always preached, namely openness and transparency.

“I have postponed publication several times over recent months, because the IPCC postponed their publication of the papers and reports.

“Whilst I know the papers I have published are a small piece of a complex jigsaw, it is the right thing to do.

“Enough is enough in my view and I encourage the IPCC to follow suit.”

The documents question the ‘evidence’, ‘objectivity’ and ‘balance’ of the IPCC's Operation Kalmia report.

Stafford Rangers footballer Kevin Nunes, from Whitmore Reans in Wolverhampton, was killed in an ‘execution-style’ shooting in a country lane in Pattingham in September 2002.

Five Black Country gangsters were jailed over the murder in 2008 but four years later had their convictions quashed after a series of failings and wrongdoing by detectives were exposed by a whistleblower.

A total of 14 former Staffordshire police officers - including Mrs Sawyers, two other ex-Chief Constables and an Assistant Chief Constable - were placed under investigation by the IPCC.

None faced any criminal charges but the IPCC’s Operation Kalmia report found senior officers should face disciplinary hearings on grounds of alleged gross misconduct.

Ultimately only one junior detective received 'management advice'.

The IPCC says it will publish its report 'as soon as possible' while ex-Derbyshire Chief Constable Mick Creedon, who carried out the watchdog's investigation, said he stands by his findings.