A judge told a jury to "man up and reach a verdict" and then had to discharge them anyway.
Judge Douglas Field issued the instruction when concerns of bias were raised during a trial when as jurors considering verdicts believed they recognised the defendant and knew him "by reputation".
John Wingrove, 40, stood accused of causing grievous bodily harm to Shane Sanderson in Salisbury, Wiltshire, on May 17 last year.
Following the one-day trial at Salisbury Crown Court, a note was passed to the court from the jury who were out deciding on their verdict.
The jury has to, in the common parlance, man up and reach a verdict in accordance with their oaths and affirmations
Two claimed to recognise Mr Wingrove and Gemma White, defending, said she had concerns "there may be some form of bias within the jury".
She explained some of them lived in the same small area in Salisbury as Mr Wingrove, and might know him "by reputation."
Ms White said: "It's a small and well-known area within Salisbury. I'm concerned that at this point there may be things said in the local area that would influence the jurors and their minds. They have concerns they are not going to be able to return a fair verdict."
Judge Field, 69, reminded the jury at the start of the trial each member was asked if they knew the defendant.
He said: "You will remember at the start of the trial each member was asked if they know the defendant, as well as being informed who the prosecution witnesses were.
"The jury has to, in the common parlance, man up and reach a verdict in accordance with their oaths and affirmations."
He asked the foreman: "Do [the two jurors in question] know this defendant?" The foreman replied: "I don't believe they know him directly, no."
Judge Field then told the jury: "Each of you took an oath or affirmation to reach a verdict on the evidence, in other words, without fear or favour.
"That is your duty as jury members - to reach a verdict based on the evidence that has been presented."
The judge then cleared the courtroom so he could ask two of the jurors further questions in private.
He then brought the rest of the jury back in and said: "I'm going to ask you all individually if you are confident of reaching a fair verdict in this trial."
The jurors said they were and the judge sent them back out to consider their verdict. However, the jury was unable to reach a unanimous decision or a majority verdict and they were discharged.
Judge Field said: "It sometimes happens. That's the way the jury system works and I thank you all for your deliberations."
The prosecution was given seven days to request a retrial and Mr Wingrove was released on bail.