Dozens of South Yorkshire Police officers are yet to speak to Hillsborough disaster investigators, it has been revealed.
The IPCC investigation into an alleged police cover-up of the reasons behind the disaster has revealed it is still waiting to contact 64 South Yorkshire Police officers 'who have not assisted' the operation so far.
The Independent Police Complaints Commission is also attempting to speak to a further 68 people connected with West Midlands Police, the force that was brought in to carry out the original investigation into the conduct of officers at Hillsborough.
Rachel Cerfontyne, deputy chair of the IPCC, said there were a number of different reasons why the 132 people are yet to speak to the IPCC.
She said the IPCC is not able to compel retired officers to attend interviews with its staff.
"Some were unable to provide an account for reasons such as poor health; others have not responded to our contact and there are a number of individuals who couldn’t be traced," she said.
"These potential witnesses have been reviewed and investigators have identified those who may have information that is of particular interest.
"We will make further efforts to persuade this group to engage with us. While the IPCC can compel serving police witnesses to attend an interview, this doesn’t apply to retired officers.
"The majority of police witnesses we have approached have helped us - we have recorded over 4,000 witness accounts during the course of the investigation and around 1,200 of those are from police officers/staff."
She added that in relation to the potential investigation into a complaint about suspended South Yorkshire Police chief constable David Crompton, the IPCC has now requested permission to access and review 'potentially relevant material' that is held by the office of crime commissioner Alan Billings.
"We are trying to progress this matter as efficiently as we can so that a decision can be made in the coming weeks," she said.
The IPCC investigations are running parallel to a criminal probe called Operation Resolve, which is looking into the planning and preparation for the match and the decisions made on the day of the disaster.
It is anticipated that both investigations will provide full files of evidence to the Crown Prosecution Service by the turn of the year.