German police are investigating the apparent murder of a prominent local politician, known for his pro-migrant views, who was found dead from a gunshot wound at his home.

Key points: Walter Luebcke was found lying in a pool of blood at his home in central Germany

Walter Luebcke was found lying in a pool of blood at his home in central Germany Police said it was unclear why the Merkel party politician had been shot

Police said it was unclear why the Merkel party politician had been shot Mr Luebcke had previously come to the attention of far-right news portals

Walter Luebcke, a member of Chancellor Angela Merkel's Christian Democrats, was found lying in a pool of blood on the terrace of his home in Kassel, about 160 kilometres north-east of Frankfurt, in the early hours of Sunday morning (local time).

He had been shot in the head.

Police from the Hesse state criminal investigation division said it remained unclear why Mr Luebcke had been shot, but they did not rule out a possible political motive.

"This first phase after the crime is very decisive for the success of the investigation," head of police Sabine Thurau said.

Walter Luebcke (right) headed the Kassel Regional Government in central Germany. ( Twitter: Hessian Ministry of Finance )

"We don't want speculation to endanger the investigation."

Mr Luebcke, who headed the Kassel Regional Government in the state of Hesse in central Germany, had previously come to the attention of far-right news outlets for speaking out in defence of migrants at the height of Europe's 2015 refugee crisis.

At that time, Ms Merkel threw open Germany's borders to more than 1 million migrants, mostly Muslims fleeing conflicts and poverty in the Middle East and beyond, a move that drew criticism from Germans on the right of the political spectrum.

Mr Luebcke gave a speech in 2015 in which he advocated "Christian values" such as loving one's neighbour, prompting at least one far-right publication to call him a "traitor" and to publish his home address.

There has been no suggestion his death is linked to the criticism.

German police have not ruled out a possible political motive. ( Reuters: Ralph Orlowski )

Reuters/AP