Right-wing extremists appear to have targeted Kabarett artist Idil Baydar for months, sending her threatening and abusive messages, German newspaper Frankfurter Rundschau (FR) reported on Tuesday.

The artist, known for her Kabarett performances that blend satire and comedy in a form of cabaret popular in Germany, is the third public figure who has been subjected to unauthorized data retrieval from a Hesse police computer, according to media reports.

Frankfurt lawyer Seda Basay-Yildiz and Janine Wissler, the leader of the Left party's parliamentary group in Hesse, were also subject of unauthorized data queries and received threatening messages.

Police are investigating all of the cases, FR reported.

Hesse state police chief Udo Münch later on Tuesday resigned over the data-breach affair, state Interior Minister Peter Beuth announced.

As the highest police official in the state, Münch took responsibility for failures "that he alone was not responsible for," said Beuth.

Police computers may be source of data

Lawyer Basay-Yildiz began to receive death threats in 2018. While no arrests have been made, an investigation shows that personal details were accessed from a computer in a Frankfurt police precinct.

A computer in Wiesbaden, around 40 kilometers (25 miles) west of Frankfurt, was used to access Wissler's personal information, according to the FR report.

Read more: Number of right-wing extremists in Germany on rise, security report suggests

Police documents do not state from where Baydar's data was accessed.

It was "inconceivable" that there had been a further data breach, tweeted Wissler, adding that she stood in solidarity with Baydar.

Neo-Nazi group reemerging?

The threatening and abusive correspondence received by Basay-Yildiz and Wissler was signed "NSU 2.0" – a reference to far-right German neo-Nazi terrorist group the National Socialist Underground (NSU) that were responsible for 10 murders in the early 2000s. 

Threats against Baydar were signed "SS Obersturmbannführer" — a paramilitary German Nazi Party rank — reported FR.

The threatening messages received by all three women "showed similarities in structure and wording," said Nadja Niesen, spokeswoman for the Public Prosecutor's Office in Frankfurt.

Police are investigating whether additional threats from unknown perpetrators were sent to other people, Niesen added. She declined to mention names, adding they had not been confirmed.

Hesse Interior Minister Peter Beuth has appointed top police official Hanspeter Mener as a special investigator to look into the case.

kmm/sms (AFP, epd)