A teenager has pleaded not guilty to manslaughter over the death of PC Andrew Harper.

The Thames Valley police officer was killed on 15 August near the village of Sulhamstead in Berkshire when he was dragged along a road by a van after responding to reports of a break-in.

The 17-year-old, who cannot be identified, also pleaded not guilty at the Old Bailey on Friday to conspiracy to steal. He was not asked to enter pleas to the further charge of murder.

Thomas King, 21, from Basingstoke, pleaded guilty to plotting to steal a quad bike before Harper’s death.

The 17-year-old, Henry Long, 18, from Mortimer in Reading, and another 17-year-old who also cannot be identified, are charged with murder, an alternative of manslaughter and conspiracy to steal a quad bike.

Three of the defendants appeared in the court from custody by video link, while King was in the dock before Mr Justice Edis. He was granted bail until his sentencing, at the conclusion of the other defendants’ trial.

A further plea hearing for Long and the other 17-year-old was fixed for 7 January. A six-week trial has been scheduled to start on 9 March at the Old Bailey.