Two of Britain’s biggest broadcasters have refused to hand over unused TV footage of recent violent unrest unless a court order is received.

The networks are holding their ground – despite a request from David Cameron that they immediately hand over such material, in order to avoid any compromise of their editorial standards.

Cameron said that the media have a “responsibility” to hand over incriminating footage to assist police in hunting down those responsible for the mayhem.

Fran Unsworth, the BBCs head of newsgathering, told Radio 4’s Media Show: “"It's a matter of principle for us, we don't just hand over our rushes [raw footage] to the police without them going through a proper process which is via the courts. It doesn't really matter what the nature of the offences are – if we went down that road of making judgments of the nature of the offences, that would compromise our editorial standards."

Under the Police and Criminal Evidence Act 1984 the police must first obtain an order from a judge before they can obtain unpublished film and photography.