Of those, 10 are in connection with the activities of the NSU neo-Nazi terror cell, which killed eight Turkish people and one Greek as well as a German policewoman over a period of seven years.
The figures have emerged in response to an information request issued by Germany's Left Party. The number does not include the five people who are already due to appear in Munich's Upper Regional Court in connection with the NSU killing spree.
One of the 14 people under investigation is Martin Wiese, who was arrested in 2003 for plotting a bomb attack on an opening ceremony for a Jewish community centre in Munich. He was later sentenced to seven years in jail for leading a terrorist organisation. He's now being accused of conspiring with a terrorist group, a charge he denies.
Another man being investigated is Meinolf Schönborn, the former head of the banned Nationalistische Front (Nationalist Front) He's accused of trying, with three others, to set up a new group called Neue Ordnung (New Order). He also denies the allegation. In northern Germany police are also investigating a handful of people thought to have helped supply weapons for attacks.
The trial of NSU member Beate Zschäpe has been marred by controversy after no Turkish media outlets initially gained accreditation to be in the courtroom to cover the trial. Though the court first refused to re-open the application process, an order from above ensured that Turkish, Greek and Persian-language media would be guaranteed seats at the trial.
Zschäpe's trial begins on May 6.