Germany’s government faced calls to toughen gun ownership laws and step up efforts to track far-Right sympathisers after the suspect in one of its worst mass shootings since World War II was found to have published a racist manifesto.

The 43-year-old presumed killer of nine people in two shisha bars in Hanau late on Wednesday had posted the document, espousing conspiracy theories and deeply racist views, online.

The suspect, who is believed to have killed himself and his mother after the shootings, belonged to a gun club, raising questions as to how a man with such ideological convictions managed to gain membership and obtain the weapons he used.

“We need new and stricter laws to regularly and thoroughly check owners of hunting and firearm licences,” Bild — Germany’s biggest-selling newspaper — wrote on its front page.“We immediately need more (intelligence) positions to monitor Right-wing radicals and intervene before it’s too late.”

Federal Prosecutor General Peter Frank said on Friday that the suspect had a licence for two weapons, and it remained unclear whether he had contacts with other far-Right sympathisers at home or abroad.

Frank added that the gunman had sent a letter to prosecutors in November complaining about an unknown intelligence agency with powers to control people's thoughts and actions, fuelling speculation he may have suffered from paranoia or other mental illnesses.

“The letter did not include his racist calls for the extermination of certain peoples,” Frank said during a news conference. “We did not launch an investigation based on the letter, which later appeared in the gunman’s racist manifesto.”

In October, Chancellor Angela Merkel’s government outlawed the sale of guns to members of extremist groups monitored by security agencies and obliged online platforms to inform police about hate content.

Those measures followed the killing of a pro-immigration German politician in June and an attack four months later on a synagogue and a kabab shop in Halle by an anti-Semitic gunman who livestreamed his actions.

At least five of the Hanau victims were Turkish nationals, Ankara’s ambassador to Berlin said on Thursday. His government demanded a robust response, calls echoed by representatives of Germany’s large Kurdish community.

Driven in part by a rise in immigration, popular support for far-Right groups is growing in Germany in conjunction with a shift away from the political mainstream.

Merkel said on Thursday that there were multiple clues that the suspected Hanau gunman had been motivated by the “poison” of racism, and that authorities would do everything possible to clarify the background to the attack.

Interior minister Horst Seehofer, leader of the Bavarian CSU, the sister party to Merkel’s CDU, said security forces have had successes in preventing hate crime, citing this month’s arrest of a far-Right group accused of planning attacks.