AN 18-year-old has pleaded guilty today (Tuesday, January 7) to manslaughter following the death of PC Andrew Harper.

Henry Long appeared at the Old Bailey today, but denied murder.

Newlywed Pc Harper, 28, died from multiple injuries after being dragged under a car on August 15 last year.

READ MORE: Crossrail delayed AGAIN 

The Thames Valley Police officer had been on duty when he was killed near Sulhamstead.

The alleged driver, Henry Long, 18, from College Piece, Mortimer, appeared at the Old Bailey for a plea hearing by video link from Belmarsh prison wearing a black and white Puma sweatshirt.

When asked for his plea to a charge of manslaughter, he said: "Pardon, was that manslaughter?" before adding: "I plead guilty, guilty."

Long denied Pc Harper's murder but admitted conspiracy to steal a quad bike.

A 17-year-old co-defendant, who cannot be identified, entered not guilty pleas to Pc Harper's manslaughter and conspiracy to steal.

The boy appeared in court by video link from Wetherby young offenders institute in a grey sweatshirt and wearing a crucifix around his neck.

Previously, another 17-year-old boy has entered not guilty pleas to manslaughter and conspiracy to steal.

READ MORE: Oxford Road closed after car ploughs into home

A fourth defendant, Thomas King, 21, from Basingstoke, had admitted conspiracy to steal a quad bike.

The three teenagers are due to face a six-week trial at the Old Bailey from March 9.

Due to the fact that legal proceedings remain active in this case, Thames Valley Police will not be making any comment at this time.