A police officer called a black suspect a 'n*****' in the back of a police van, a court has heard.
PC Alex MacFarlane was recorded on a mobile phone by Mauro Demetrio, saying: 'The problem with you is you will always be a n*****.'
Jurors heard recordings of the 53-year-old, where he called the suspect a 'scumbag', 'c***' and referred to having sex with the detained man's mother, as he was being taken to a police station during the London riots in August 2011.
Mr Demetrio had been pulled over by police on suspicion of drug-driving and had become 'abusive' after allegedly being strangled by another Metropolitan police force officer.
In a police interview read to the court, PC MacFarlane admitted getting into a 'slanging match' with the suspect.
'I have to confess it became a bit unpleasant,' he said.
PC MacFarlane said he may have used the word 'n*****' but denies intending to cause harassment or distress to Mr Demetrio.
Prosecutor Duncan Atkinson told the jury the officer's outburst was recorded by Mr Demetrio so there could be 'no dispute' that MacFarlane had uttered the comments. Under cross-examination, Mr Demetrio said the alleged slur 'made me feel like s***'.
The court heard Mr Demetrio had also been detained as he was wanted on suspicion of supplying drugs and failing to attend court. No action was taken on the drug-drive arrest.
PC MacFarlane is alleged to have abused the suspect on the way to Forest Gate police station, east London. He was charged with racially aggravated harassment as a result of the mobile phone footage after prosecutors initially ruled out taking action against him.
The trial at Southwark crown court continues.