A Metropolitan Police constable accused of racially abusing a suspect following last year's August riots has been discharged after a jury failed to reach a verdict in his trial for a second time.
A mobile phone recording heard Pc Alex MacFarlane, 53, tell 22-year-old Mauro Demetrio: "The problem with you is you'll always be a n*****."
He also said: "Be proud of who you are.
"Don't hide behind your black skin."
The conversation took place after Demetrio had been arrested on suspicion of drink or drug-driving and was taken to Forest Gate police station, east London, on 11 August.
Southwark Crown Court in London heard MacFarlane admit to using the word "n*****" but said it was not intended as a racist insult.
He denied a charge of racially aggravated intentional harassment.
The jury, of five women and seven men, told Judge Gledhill QC they could not agree on a verdict after being told they could return a majority decision.
MacFarlane, a serving officer with the Met for 18 years, acknowledged during the trial that he should not have used the word "n*****".
During the first trial, Richard Atchley, defending, said MacFarlane accepted he had used the word n***** in an "error of judgment" but denied it was used in a racist manner.
"He did it, effectively, as a response to Demetrio's negative self-esteem," Atchley said.
The married father-of-two said he was "exhausted" at the time of the incident after working 66 hours between 6 and 11 August following the riots which swept London.
It was also alleged by Demetrio that MacFarlane made a sexual reference about the suspect's mother and that he would be dead in five years, which the officer denied.
After agreeing that MacFarlane could walk free from court, Judge Gledhill QC said the officer had used the term in a "momentary loss of judgment".
"It is clear to me that immediately having used the word which should never have been said, particularly by an experienced officer, he realised what he had said... and tried to undo the damage," he said.
Mr Atchley said the officer would now face disciplinary proceedings following the case.