Passau, Germany - A German police chief wounded in a knife attack by a suspected neo-Nazi was released from hospital on Friday as a search for the assailant continued.

Alois Mannichl, 52, chief of police in the southern city of Passau, was stabbed in the stomach outside his home by a skinhead who yelled neo-Nazi abuse at him, then left with a getaway driver.

A 33-year-old man and his wife, aged 22, were arrested three days after the December 13 attack on charges of complicity in attempted murder after police traced the getaway car to them.

Both suspects were known to police for connections to Germany's right-wing scene.

Police suspect Mannichl was the victim of a revenge attack by neo-Nazis because of his attempts to keep them under control. He has been vilified on websites popular with neo-Nazis.

Mannichl said on leaving the clinic that he would not be intimidated by right-wing extremists. He would continue to crack down on neo-Nazis, he added.

Police earlier released a description of the attacker, whom they believe to be part of Bavaria neo-Nazi scene. The man is thought to be between 25-35 years old, 1.90 metres tall, and speaks with a Bavarian accent.

The assailant reportedly used Mannichl's own knife, which had been left outside the door of the police chief's home. Police have set up a 50-member crime squad to catch the man.

There are around 31,000 members of extreme right-wing groups in Germany, about 10,000 of whom are prepared to resort to violence, according to the domestic intelligence agency, the Office for the Protection of the Constitution.

The violence, with its implication that rightists are willing to attack public officials, has led to renewed calls to outlaw Germany's main far right group, the National Democratic Party (NPD).

An earlier attempt to ban the anti-foreigner party was quashed by Germany's top court in 2003. (dpa)