German police allegedly leaked details to a far-right group about an Iraqi man accused of carrying out a fatal stabbing, triggering violent anti-migrant protests.

Authorities in the state of Saxony have launched an investigation after the 22-year-old suspect's arrest warrant was apparently shared with Lutz Bachmann of the far-right movement Pegida.

The document revealed the Iraqi man’s full name along with that of the second suspect, a 23-year-old Syrian man.

Details about the victim, a 35-year-old German identified only as Daniel H, witnesses and the judge were also contained in the document, which was posted online by Mr Bachmann.

Martin Dulig, Saxony’s deputy prime minister, said it was a “scandal” that “some police officers think they can leak things like this even though they know they're committing an offence”.

Horst Seehofer, Germany’s national interior minister, said the leak was "completely unacceptable".

An investigation has been launched by German police into whether official secrets rules were breached.

The stabbing in the town of Chemnitz provoked two days of protests, including clashes between far-right and left demonstrators.

The 35-year-old German man died in hospital following a 'dispute between several people of different nationalities', police said (Getty)

At least five people are facing charges for performing the “Hitler salute”, which is banned in Germany.

The stabbing and the protests have exposed deep divisions in German society over the influx of more than one million refugees and migrants since 2015.

Angela Merkel repeated her condemnation of both the stabbing and the protests on Tuesday. She said the scenes filmed on mobile phones of migrants being chased through the streets, were completely unacceptable in a state based on the rule of law.

Michael Kretschmer, the prime minister of Saxony and a close ally of Ms Merkel, vowed to deal firmly with extremists in his state which has long been a hotbed of support for far-right parties.

Pegida led calls for protests after the man's death (Getty)

The Chemnitz leak is the latest in a string of incidents that have given rise to claims of a far-right infiltration of police forces in Saxony.

Last week police in Dresden detained a film crew who were videoing a far-right protest against Ms Merkel.

The arrests were made after a protester – who it later emerged was a state police employee – claimed to have been verbally abused during a march in support of Pegida.