Human rights groups applauded the appeal ruling by an administrative tribunal in the city of Koblenz, saying it would prevent police profiling of non-whites.

Police had charged the 26-year-old man, who was not named in public, with criminal insult. He had argued with two police officers who asked to see his ID on a train ride from Kassel to Frankfurt.

One federal policeman had testified that that he was on the lookout for illegal immigrants and he used skin colour to select which people to conduct spot checks on.

"This ID check was contrary to law because it was mainly prompted by skin colour," a court spokesman said.

Federal police apologized in the courtroom to the 26-year-old student, who had lost his lower-level case to have the police actions declared illegal and void but was vindicated on appeal.

In a written statement through his lawyer, Sven Adam, the student said, "This has been a long battle to make federal police obey the ban on discrimination."

Amnesty International called the ruling "a major signal" to the police. The German Human Rights Institute said police must now act to alter police practices. But a police union attacked the ruling "for not making policing any easier."

"Once again, the courts are making aesthetic improvements to the law and ignoring the practical side," said Rainer Wendt, chief of the DPolG police union.