Instead police are hoping to learn the whereabouts of the stabbing suspect from them, senior public prosecutor Helmut Walch told the station.

A tip about a car licence plate seen near the crime scene led police to the man and a woman – both thought to be involved in far-right extremist activities – in Lower Bavaria. Both are from Munich.

Investigators revealed that the man and woman had both been present at the Passau burial of Nazi Friedhelm Busse this summer. Police have created tension with far-right groups in the region after they had Busse exhumed to remove an illegal Nazi flag that a witness saw buried with him.

Two male suspects in the stabbing arrested earlier this week were released when they were able to provide convincing alibis and did not match DNA traces left at the crime scene Walch said. Mannichl also did not recognize photos of the 26 and 27-year-old suspects.

These two suspects were arrested not far from 52-year-old Mannichl’s home near Passau, where he was found slumped on his porch with stab wounds to his abdomen.

Local newspaper Am Sonntag reported Mannichl answered his front door on Saturday to a tall skinhead at around 5:30 pm. The man said something along the lines of “Greetings from the national resistance,” and said, “You leftist pig cop, you won’t trample on the graves of our comrades any more,” before stabbing Mannichl in the stomach with a 12-centimetre knife.

He then threw the knife away in the garden and ran to a waiting car in a nearby street and was driven away.

Senior public prosecutor Walch said Monday afternoon that the knife used in the attack belonged to Mannichl, who had apparently used it earlier to cut Lebkuchen Christmas sweets at a neighbour’s party. He left the knife on his porch afterwards. Walch said police were not ruling out a premeditated crime, though.

Mannichl was seriously wounded, but is now recovering after an operation.

Bavarian State Premier Horst Seehofer said on Sunday evening that this “new dimension” of right-wing extremist violence required a “new and very clear and hard answer from the state.”