Editor's note: This report contains offensive language.
LONDON (CNN) -- One of England's biggest soccer stars went on trial Monday, accused of hurling racist abuse at another player during a match last year.
The normally staid chambers of Westminster Magistrates' Court in London got an earful of shockingly foul language as lawyers and witnesses detailed what Chelsea captain John Terry said to Queens Park Rangers defender Anton Ferdinand in the match.
Terry did not deny directing a barrage of foul language at Ferdinand and referring to him as "black," but he denied engaging in racist abuse.
The highly unusual criminal prosecution over words uttered on a soccer field comes as English soccer officials fight to stamp racism out of the sport, with mixed results.
Liverpool player Luis Suarez was banned for eight matches when the Football Association, the English sport's governing body, found he had racially abused Manchester United defender Patrice Evra.
The chanting of racist abuse by fans also remains a sporadic problem in soccer across Europe.
The Crown Prosecution Service is pressing charges against Terry for a "racially aggravated public order offense" because of the comments during an October 23 match between Chelsea and Queens Park Rangers.
Prosecutors played a video of the incident, without sound, as the case opened Monday morning.
The alleged abuse came after Ferdinand knocked Terry down during the game, the jury heard.
When he got up, Terry made a gesture as if Ferdinand's breath smelled, and he called Ferdinand a "c...," prosecutor Duncan Penny told the court.
Ferdinand responded with the same word, saying it described Terry, not him, because Terry had had sex with a teammate's wife, the prosecutor said.
Ferdinand also made an obscene gesture related to sex as Terry ran back into position, Penny said.
Ferdinand testified that he did not hear the comments Terry made at him, but that he would have been "hurt and disappointed" if he had heard Terry call him a "black c..."
"When someone brings your color into it, it takes it to another level and it's very hurtful," Ferdinand said.
Terry maintains that Ferdinand knocked him down before the incident and that the two then exchanged "normal football verbals."
He told Football Association officials that he then repeated to Ferdinand words he thought the opposing player had said to him, Penny told the court Monday.
The maximum penalty for the offense is £2,500 (about $3,900).
That would be a drop in the bucket for a player worth millions, but a criminal conviction could lead to action against him by his team or England's Football Association.
Terry was captain of England's national team at the time of the incident but was stripped of his captaincy after a preliminary court hearing on the racism charge in February.
He remained captain of Chelsea, which went on to win the prestigious Europe-wide Champions League this year.
The trial could last up to five days, court officials say.