Material from the Hillsborough inquests suggests that South Yorkshire Police was trying to "spread the blame" during the long-running hearings into the deaths of 96 football fans, according to a review by a leading QC.
Independent barrister Hugh Tomlinson QC criticised the embattled force but agreed with a decision by the Independent Police Complaints Commission (IPCC) not to investigate its former chief constable, David Crompton, over how he instructed his lawyers acting in the inquest hearings.
In the conclusion to his report, Mr Tomlinson said it was "highly regrettable" that Mr Crompton did not instruct his lawyers to "make a clear distinction" between the position of his force and that of individual senior officers represented at the inquests, including match commander Chief Superintendent David Duckenfield.
The barrister said: "Finally, I would say that the material relied on by the complainants does suggest that the SYP (South Yorkshire Police) were indeed trying to 'spread the blame'.
"The approach of the SYP can, in my view, properly be criticised. In the context of the inquests - and bearing in mind the position being taken by the ex-senior officers - there was a clear risk of confusion.
"Mr Crompton's apparent failure to instruct the SYP legal team to make clear the distinction between their position and that of the ex-senior officers is highly regrettable."
But Mr Tomlinson said this failure was very different from "a deliberate decision by Mr Crompton to instruct the SYP legal team to advance an improper case which was contrary to the SYP's public position".
He said the IPCC was been asked to investigate "deliberate wrongdoing rather than poor judgment" and he concluded: "There is no evidence to suggest that Mr Crompton gave instructions to advance an improper case and, as a result, there are no reasonable grounds to investigate the complaint."
Mr Tomlinson was brought in by the IPCC to review its decision last month not to investigate complaints from some of the bereaved families that Mr Crompton instructed lawyers to "pour blame" on Liverpool fans at the Hillsborough inquests.
A former police press officer has also alleged that the South Yorkshire force had been seeking to "spread the blame" during the two-year-long hearings.
Mr Crompton is currently mounting a legal fight against a decision by South Yorkshire's Police and Crime Commissioner, Alan Billings, to effectively sack him over comments he made in the wake of the inquests earlier this year.
Mr Tomlinson said it was "regrettable" that South Yorkshire Police refused to waive the privilege which means that instructions given to lawyers by clients are confidential.
But the QC said that this refusal was not enough, in itself, to prevent the IPCC from mounting an investigation.
He said the families had highlighted a number of areas of concern over the South Yorkshire Police's legal team's approach during the inquest.
The barrister said these included a refusal of the force to indicate to the coroner whether it was intending to contend that drink was a factor in the disaster and questions asked by the force's leading barrister, Fiona Barton QC, relating to supporter behaviour which "tended to suggest that this was or could have been a factor which contributed to the disaster".
He said there were also questions asked by Ms Barton tending to suggest that others, such as Sheffield Wednesday FC and Sheffield City Council, bore responsibility for the disaster and questions which suggested the crucial opening of a gate to the ground at the Leppings Lane end was not the result of an order from Chief Superintendent Duckenfield.
Mr Tomlinson said there was "considerable force" in the argument that South Yorkshire Police's "silence" when the ex-senior officers repeated denials made in the past meant that an "individual juror" would have seen "the police" as a single group attacking the supporters and raising "hooliganism" as an important issue.
He said: "The stance taken by the ex-senior officers was crucially different from that of the SYP. However, some of the questioning by Ms Barton QC would, in my view, be likely to have given the jury the clear impression that the SYP was supporting the position of its former officers. This was most unfortunate.
"It can properly be inferred that Mr Crompton did not give the SYP legal team clear instructions to avoid such an impression being given. I can well understand that the failure by the SYP to distance itself from the ex-senior officers would have been extremely upsetting for the Hillsborough families and had the potential to confuse the jury.
"The position was made worse by questioning by Ms Barton QC which, although within the ambit of her instructions, was not in the words of the coroner "wise".
But the QC agreed with the IPCC that the force did not advance a "particular scenario" and that the questions asked by the South Yorkshire Police barristers about fan behaviour were "not part of a deliberate, predetermined strategy".
The inquests, which found that the 96 victims of the disaster had been unlawfully killed, were the longest jury cases in British legal history.
In the wake of the verdicts, then-shadow home secretary Andy Burnham accused South Yorkshire Police of ''protecting itself above protecting people'' during the hearings, and said that the families had been ''through hell again'' during the protracted case.
The IPCC said it had not found any evidence to support allegations by former South Yorkshire Police press officer Hayley Court that she was told to "smooze" the media by a senior officer and encourage reporting which placed the force in more favourable light.
Ms Court, who was brought in by South Yorkshire Police specifically to support the Hillsborough inquests team, told The Guardian in May: "The South Yorkshire police, having made a full apology for the Hillsborough disaster in 2012, should not have been seeking to spread the blame on to others, including Liverpool supporters, at the inquests, and seeking to influence the media to take that line."
She said: "I tried to make this point in every formal way within the South Yorkshire police, but in response I faced criticism for my own performance and felt bullied."
But, in a report published on Tuesday, an IPCC investigator said: "Having reviewed the available evidence in this case, I am satisfied that Hayley Court was instructed to forge a working relationship with the media at the inquests.
"I am also satisfied that this instruction may have been repeated to her on a number of occasions, particularly as it appears there were concerns raised about her performance in this area.
"However, none of the witnesses have provided any evidence to support Hayley Court's allegations that an instruction was given to deliberately and unethically attempt to manipulate the media.
"Nor has any witness provided any evidence to suggest that the superintendent's behaviour throughout the inquests was anything other than professional and in accordance with a desire to see balanced, accurate court reporting."