A weapons dealer thought to have sold a gun to the 18-year-old who carried out a deadly shooting rampage in Munich has been detained, German prosecutors said.
Police captured the 31-year-old on Tuesday in the central university town of Marburg after luring him into a dummy transaction, prosecutors and the customs investigations office in Frankfurt said.
Ali David Sonboly, a teen of Iranian-German nationality, gunned down nine people before shooting himself at a Munich shopping centre on July 22. He is thought to have purchased the Glock 17 pistol and ammunition used in the attack on the dark web.
Investigators carried out a bogus transaction to catch the suspected arms dealer admitting to conducting the sale. He reportedly told undercover police that he had met with the assailant twice in Marburg, once in May to sell him the weapon used in the shooting, and then again four days before the attack to sell him the ammunition.
This corresponded with information gathered in investigations by Munich's state prosecution service and the state police of Bavaria.
Marburg is situated in the state of Hesse and lies around 400 kilometres north-west of Munich.
Police in Hesse confiscated a machine gun earmarked for sale from the suspected dealer on Tuesday, as well as another pistol and ammunition.
The man was also carrying a loaded gun when police found him.