She said the IPCC was discussing setting up a "challenge group" of independent people who can scrutinise the work of both the IPCC and the office of the Director of Public Prosecutions (DPP) to keep the families updated about the progress, independence and robustness of the work.

BBC: Hillsborough inquests date set for next week

If the Director of Public Prosecutions agrees to a review, it is likely that the Crown Prosecution Service and attorney general's office will decide which types of case come under the microscope.

BBC: DNA doubt cast over other murders