The judge presiding over the trial of three teenagers responsible for the death of Pc Andrew Harper has ruled out the possibility jurors being subject to “improper pressure” to find them not guilty of murder.

Mr Justice Edis took the unusual step at the Old Bailey hearing on Friday of addressing concerns about the jury’s verdicts, telling those present he had “deliberately” not read press reports, but had become aware of some element of “controversy”.

It came after Pc Harper’s widow, Lissie, called on the Government to order an unlikely retrial in the hope of getting a murder conviction.

The original trial was abandoned the day the country went into lockdown in March, while extra security measures were ordered for the retrial, which started on June 23, amid fears of potential juror intimidation by supporters of the defendants.

And a female juror was discharged just a day before the remaining 11 started deliberating on their verdicts after she was seen by a prison officer to mouth “Bye boys” to the teenagers in the dock.

Henry Long, 19, and 18-year-olds Jessie Cole and Albert Bowers are being sentenced for manslaughter.

Addressing the court on Friday morning, the judge said: “These verdicts have caused some controversy.

“I have deliberately avoided reading or viewing reports of the case and comment on it, because I have a duty to do justice in accordance with the law and the evidence which I have heard.

“However, I have been made aware that there has been some discussion about the trial and, in particular, the measures which were in place for the protection of the jury.

“It may be believed in some quarters that the jury was subject to some improper pressure.

“To the best of my knowledge and belief there is no truth in that at all.”

The judge said jurors were given extra security, including being sworn by number so that their names were not in the public domain.

He said the court was informed in March that the police held information that “associates of the defendants planned to follow members of the jury with intent to intimidate them”.

But he said the information was not corroborated and “nothing at all untoward happened during the first trial”.

He said no jurors reported concerns to court staff.