Why not just hand it over?

From the Horse and Hound I note that the Independent Police Complaints Commission, who are looking into complaints regarding police behaviour at the pro-hunt demo in parliament square, are experiencing some difficulties trying to review video and stills evidence of the demonstration:

...progress is proving slow because some of these organisations, led by the Guardian Media Group, have declined to provide CCTV and still photographic evidence, and are currently judicially reviewing the Crown Court order to hand such media over.