More than three decades after the attack, investigators have found concrete evidence of the long-held belief that there was more than one perpetrator for the so-called Wiesn attack.
"Today, I have ordered that the investigation be re-opened," said chief federal prosecutor Harald Range on Thursday from his office in Karlsruhe.
"Murder does not fall under the statute of limitations," he added.
In 1980, a group of right-wing radicals set off an explosion at the main entrance of Oktoberfest in Munich on September 26. In the explosion, 13 people were killed and a further 211 were injured.
To date, the attack has been credited to 21-year-old Gundolf Köhler, who died when placing the explosive. He was a member of the group neo-nazi group Wehrsportgruppe Hoffmann.
In the course of the investigation, more perpetrators were sought out, but all investigations led to a dead end.
"We're in a new situation," said Range, though would not elaborate on the evidence.
The grounds for the new investigation are tied to a witness that came forward in September, who has proven "credible", said Range. They say the woman knows of evidence that there was more than one person behind the attack.
"We have never pursued the theory of a single perpetrator," said Range, though prosecutors were never able to gather enough evidence about the case, even after the Stasi files were opened to the public.
According to a report in the Süddeutsche Zeitung, the woman had received a leaflet with an obituary for Gundolf Köhler before he was publicly known as the bomber. She came forward with the lawyer for the victims, who has petitioned the federal prosecutors four times on the anniversary of the attack for a new investigation.