Despite six criminal investigations, it has been claimed that police corruption prevented private investigator Daniel Morgan's murder in 1987 from being solved.
Mr Morgan's brother Alastair told the BBC's Newsnight: "If we're going to deal with corruption in the police force, we have to look at it straight in the eye.
"We have to see how it works, the nuts and bolts of it, where it started, what decisions were made."
More top news
A defence ministry official reportedly said Russia had intensified its campaign in the last 24 hours, with 64 sorties hitting 55 targets.
Some patchy mist and fog overnight as the temperature's dip.
The actor joined hundreds of mourners at the funeral of the 30-year-old make up artist in the village of Cappawhite, Ireland.