The Frankfurter Allgemeine Zeitung (FAZ) said police had on Saturday extensively interviewed the suspect, a "younger man," who it said had "admitted" to having been in a "private relationship" with the conservative politician.

"What exactly this contact looked like still needs further investigation," FAZ reported, adding that investigators were confident they had identified the suspect by examining the dead politician's private data, including that on a mobile telephone.

Germany's dpa news agency subsequently quoted a police squad spokesperson as saying that one person who had been taken into custody was released after questioning.

The LKA criminal investigations office of Germany's central state of Hesse had earlier in the week taken calls from some 80 people responding to a televised crime probe program after doubting suicide as the cause and establishing a special unit comprising 50 detectives.

Lübcke had previously received death threats for standing up to the far right

Police scanned photos, video footage

Forensic work at his home had been wrapped up on Friday, police said. Detectives had minutely scanned photos and video footage filmed at a town fair immediately adjacent to Lübcke's home.

Lübcke, 65, had for 10 years been the Kassel region's municipal-oversight president, a senior civil servant role with regional powers, for example, over local body compliance, workplace safety, transport planning and environmental protection.

He was found shot in the head at close range after midnight last Sunday. Attempts to resuscitate him failed.

Death threats previously received

A political motive was initially not ruled out, given that Lübcke had previously received death threats for standing up to the far right.

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At the height of Europe's refugee crisis in 2015, Lübcke had defended migrants as people in need of basic Christian values.

Police also looked into hateful social media comments posted after his death, while German Federal President Frank-Walter Steinmeier said such slander was "repugnant."

As a member of Chancellor Angela Merkel's governing Christian Democrats (CDU), Lübcke had also served in Hesse's state assembly from 1999 until 2009.

From 1986 until 1999, he had directed an institute for vocational and political education at Rosbach, north of Frankfurt, the commercial hub in Hesse, which has its state assembly in Wiesbaden.

ipj/rc (APF, dpa)

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