The jury in the Old Bailey trial of three teenagers for the murder of Pc Andrew Harper has been discharged due to the coronavirus pandemic.
Henry Long (18) and two 17-year-old boys were accused of killing Pc Harper in August last year.
The 28-year-old Thames Valley officer became entangled in a tow rope as he tried to apprehend quad bike thieves, jurors were told.
The stricken officer was probably knocked unconscious as he fell, then dragged more than a mile along country lanes behind a Seat Toledo car driven by Long, the court was told.
Colleagues tried to save him but he suffered catastrophic injuries and died at the scene near Sulhamstead in Berkshire.
Long of Mortimer, Reading, admitted manslaughter and conspiracy to steal a quad bike but denied murder.
The two youths who cannot be named for legal reasons admitted conspiracy to steal but denied murder and manslaughter.
Pc Harper’s widow Lissie and other family members attended the trial, which opened on March 10. Over two weeks the jury viewed harrowing dash-cam footage and heard a string of eyewitness accounts.
Last week the jury dropped from 12 men and women to 10 due to jurors going into self-isolation.
Yesterday Mr Justice Edis made a statement in court that the remaining jurors were discharged and the trial adjourned.
He said he had made the decision with a “heavy heart” after a third juror went into isolation over the weekend.
He said: “It is with great regret that I have decided to discharge the jury and to adjourn this trial.
“I have taken this decision with a heavy heart because I am acutely conscious of the need of those who loved Police Constable Harper, who would have been 29 yesterday, for this process to come to a conclusion.”
The judge set a review hearing on June 1 to set a date for the trial to start again.