A junior politician in the Left party who claimed to have been the victim of a homophobic, neo-Nazi knife attack faces up to three years in jail for lying.

19-year-old Julian Kinzel alleged in January that right wing extremists slashed him 17 times with a knife while calling him a “gay communist”. In the aftermath of the attack Mr Kinzel, who is heterosexual, posted a message on Facebook declaring that he would not be intimidated.

On the social media website he urged other left wingers to stand against “inhuman and violent ideologies”.

On Thursday, however, the prosecutor in the city of Schwerin accused Mr Kinzel of faking a crime. According to the Left the 19-year-old who, at the time of his allegations, represented them as a local politician, is no longer a member of the party. He is now facing either three years in prison or a fine.

Doubts about the the politician’s story surfaced not long after it became public. A number of inconsistencies in his story, not least inexplicable injuries, led to police opening the investigation against Mr Kinzel.

A doctor’s report, looking into the incident, showed just days after the alleged attack that the nature of the man’s wounds were inconsistent with his description of the assault. It noted that the cuts appeared to be “self-inflicted”.

Still, figures in Mr Kinzel’s party stood behind him, Dietmar Bartsch, head of the Left in the Bundestag, condemned the alleged knife attack “in the strongest terms”, and pledged that the party would never give up the fight against right-wing extremism.

When doubt was doubt on his young colleague’s story, Bartsch said ridicule of Mr Kinzer is “misguided”. The veteran Bundestag member added “there are too many real attacks by right wing extremists and racists towards refugees … their supporters, and politically alternative thinkers”.

Germany saw a similar case some years ago, when a young woman claimed to have been attacked by four youths in a parking lot. The 17-year-old said neo-Nazis had carved a swastika on her hip after she had rushed to the help of a migrant child. A court ruled that the injury was self-inflicted, and sentenced the woman to 40 hours of community service.