The Islamic State's (Isis) well-oiled propaganda machine took a new twist releasing a threat against Germany in the form of a music video reportedly sung by a Berlin rapper turn jihadist.

The clip features a German voice, believed to be that of 39-year-old Denis Cuspert, who went by the stage name of Deso Dogg, singing of terror attacks in Europe, over footage including images from the Islamist shootings in Paris earlier this year.

"In France deeds were done, in Germany the sleepers are waiting," the voice sings. "War has just begun, we have smelled blood".

The track call on Muslims in Europe to pick up a knife and stab their "infidel" neighbours while showing jihadists wearing a suicide vest or aiming with a sniper rifle.

"Allah will reward you," the man sings in the slick video. "Put an end to the filthy ones."

IS militants said the voice is that of Deso Dogg, although the ex-gangsta rapper does not appear on camera, fuelling rumours he has been wounded. Unconfirmed reports emerged last year, claiming he had been killed during fighting.

Cuspert, who now goes by the nome de guerre Abu Talha al Almani, has appeared in other IS propaganda films, including one in which he was seen holding aloft a severed head.

A Muslim convert who holds previous prison convictions and was born to a German mother and a Ghanaian father, he arrived in Syria in 2013 via Egypt.

In February federal prosecutors opened an investigation for war crimes against him.