Jurors in a manslaughter trial were followed from a Crown court and offered £500 bribes, a court heard.
It is alleged jury members were also filmed after a fire alarm was deliberately set off in a bid to disrupt the proceedings in the case at Leeds Crown Court.
Three men are on trial accused of conspiracy to pervert the course of justice by interfering with the deliberations of members of a jury.
A jury hearing the case were told five other men have already pleaded guilty to the same charge.
Peter Moulson, QC, said the charges were in relation to a 'cash for crash' manslaughter trial held at the court in February this year.
Mr Moulson said those involved in the conspiracy sought to get the jury to return not guilty verdicts or to disrupt the case in order to secure a retrial.
The court heard a 15-year-old girl was "recruited" by the conspirators to approach three jurors as they left the court building on Oxford Row, in Leeds city centre.
He said: "She approached three of the jurors while they were walking away and offered them £500 to return guilty verdicts.
"We say that she got her words wrong. She was described by the jurors who were approached by her as frightened."
Mr Moulson said another man, Jamie Lee Lawson, approached another juror and offered £500 for a not guilty verdict.
A fifth juror was followed by another man, Zafarullah Ahmed, into the centre of Leeds.
Mr Moulson said the approaches took place on the afternoon in February 21 this year.
He added: "Those activities were essentially the culmination of a plan which had been put in place."
The prosecutor said a fire alarm was deliberately activated by Waqas Ahmad in the court's cafeteria the previous day, Monday February 20, so the building would be evacuated for an extended period of time.
My Moulson said one of the men on trial, Haroon Sharif, filmed jurors in the manslaughter trial as they stood at the rear of the building at a muster point.
The court heard the attempts to disrupt the trial were made as the jury retired to consider verdicts after hearing evidence in the trial against three defendants - Raja Zohib Hussain, Shahrear Islam-Miah and Sabir Hussain.
Mr Moulson said the men were charged with manslaughter and conspiracy to defraud in a 'cash for crash' incident.
He said: "The significantly serious element of that case was that during the deliberate collision they killed the occupant of the vehicle in which they deliberately collided, giving rise to the charge of manslaughter.
"The consequences of being convicted of manslaughter were obviously serious."
Shahrear Islam-Miah, 27, of no fixed address; Haroon Sharif, 21, of Hale Barn, Altringham, and Abdilahi Ahmed, 26, of Lincoln Towers, Burmantofts, Leeds, plead not guilty to conspiracy to pervert the course of justice.
Five defendants have pleaded guilty to the charge. They are: Jonaade Raja Hussain, 27, of Ring Road, Beeston, Leeds; Zafarullah Ahmad, 21, of Hamilton Avenue, Leeds; Raja Zohib Hussain, 31, of no fixed address; Waqas Ahmad, of Hamilton Avenue, Leeds, and Jamie Lee Lawson, 28, of Bayswater Grove, Harehills, Leeds.
The trial continues.