Police in Berlin have launched an investigation into officers suspected of using a chat group on their mobile phones to exchange racist messages about African and Muslim migrants, a police spokesman said on Thursday.
The allegations, first exposed by public television ARD, are the latest embarrassment for the German police, which is under pressure to take tougher action against those in its ranks with extreme views and far-right sympathies.
In September, officials in the western region of North Rhine-Westphalia suspended 29 officers for sharing pictures of Adolf Hitler and of doctored depictions of refugees in gas chambers on their mobile phones.
In a country with painful memories of the World War Two genocide of millions of Jews by the Nazis, some politicians have called for a national commission to investigate the extent of racism within the police and security services.
Interior Minister Horst Seehofer, a conservative ally of Chancellor Angela Merkel, has resisted such calls.
ARD's Monitor programme discovered racist exchanges involving more than 25 policemen in Berlin through two whistleblowers, including an officer who was a member of the chat group.
A police spokesman said such messages are punishable by law.
"Based on our knowledge of the facts we have immediately launched criminal proceedings and an investigation," Berlin police spokesman Thilo Cablitz said in a statement.