Comments about the Hillsborough disaster made by a chief constable in an email will be investigated by another top police officer, a police and crime commissioner (PCC) has confirmed.
South Yorkshire PCC Shaun Wright said he has received a complaint regarding the content of emails sent by South Yorkshire chief David Crompton.
Chief Constable David Crompton said he thought the matter had already been dealt with
Mr Crompton sent a message to his senior staff last year which appeared to suggest a campaign group representing families of those who died was not telling the full truth about the 1989 tragedy.
The email read: ''One thing is certain - the Hillsborough Campaign for Justice will be doing their version ... in fact their version of certain events has become 'the truth' even though it isn't!!
''I just have the feeling that the media 'machine' favours the families and not us, so we need to be a bit more innovative in our response to have a fighting chance otherwise we will just be roadkill.''
Mr Wright said the chief constable of Cambridgeshire, Simon Parr , will now investigate. Mr Crompton said on Friday he had thought the matter was "completely closed" after he apologised earlier this year.
The PCC said: "I have today recorded a complaint against the chief constable of South Yorkshire Police, David Crompton, in relation to internal emails concerning the Hillsborough tragedy and its aftermath.
"The request has been submitted by a firm of solicitors in Liverpool acting on behalf of a number of individuals affected by the event. This is a formal complaint, which must be dealt with in accordance with statutory procedures.
"I have appointed an independent investigating officer, chief constable Simon Parr of Cambridgeshire Constabulary, to investigate the complaint."
96 Liverpool fans died in the Hillsborough tragedy
But on Friday Mr Crompton said: "In February this year I apologised for the wording of an email.
"The Independent Police Complaints Commission (IPCC) looked into the matter at the request of the crime commissioner and publicly concluded that no formal disciplinary proceedings were justified.
"Nothing has changed since then. No new material is available now which was not available in February.
"I had understood the matter to be completely closed but will co-operate fully with any investigation if requested to do so.
"At this stage it would be inappropriate to comment any further."
The internal email, which came to light following a Freedom of Information request, was sent as part of South Yorkshire Police's preparations for the publication of the Hillsborough Independent Panel report last year.
It discussed how the force could use its website to respond to the findings of the panel.
It revealed how dozens of police statements had been altered to portray police in a better light.
South Yorkshire Police's response to the tragedy is currently subject to a huge inquiry by the Independent Police Complaints Commission (IPCC).
In February, IPCC commissioner Nicholas Long said the majority of the emails and documents he considered ''raises no issues''.
But he said one email from the chief constable ''caused me concern''.
He said: ''I consider that this is at best ill-judged, and at worst offensive and upsetting."
At the time, Mr Crompton said the email, sent to his assistant chief constable and head of press and communications, was not meant to cause offence and apologised.