The sister of a man who died in police custody in Hull has lost a racial discrimination case against the Crown Prosecution Service.
Janet Alder alleged the CPS racially discriminated against her during her dealings with them after the death of her brother, Christopher.
Judge Penelope Belcher, at Leeds County Court, said she shared concerns that racism played a part in his death.
But she dismissed claims that Ms Alder was treated in a racist manner.
Mr Alder, 37, choked to death while handcuffed and lying on the floor of a Hull police station in 1998.
After his death a coroner's jury returned a verdict of unlawful killing at an inquest.
In 2002 five Humberside Police officers went on trial accused of manslaughter and misconduct in public office. They were cleared of all charges at Teesside Crown Court.
During the discrimination hearing, between 20 September and 3 December 2010, Ms Alder said she believed crucial information relating to race was left out of the trial because people involved in the prosecution did not want them to be convicted.
She said analysis of the video of the events in the custody suite revealed the sound of monkey noises being made and that one officer is heard referring to "banana boats".
Cathryn McGahey, for the CPS, said lawyers involved in the case had told her these matters were not put before the jury for evidential reasons.
Miss McGahey said the CPS explained how they could not disprove one officer's account that he was referring to "banana boots" - the yellow, fabric footwear sometimes given to prisoners.
She also said it was explained to Ms Alder how the issue of the alleged monkey noises could not be put before a jury because it was impossible to say who had made the sounds.
Judge Belcher, who has now published her judgement, said: "In conclusion, I understand and indeed share Miss Alder's concerns as to the possibility that racial discrimination played some part in the actions of the police officers on the night that Christopher Alder died.
"I also understand and share her concerns as to the standard of the investigation undertaken by West Yorkshire Police into the actions of the Humberside officers.
"However, she has failed to satisfy me on a balance of probabilities that any actions by the CPS in this case involved racial discrimination by the CPS in their dealings with her.
"It follows that her claim in this action is dismissed."