Hans-Georg Maassen, the former head of Germany's Office for the Protection of the Constitution (BfV) — the domestic intelligence service — has often drawn fire for his remarks and actions.

Maassen gained notoriety in 2002 while working for the German Interior Ministry and arguing that Murat Kurnaz, a German resident held in the US prison at Guantanamo for five years before being released, could not return to Germany because his residency had lapsed. Herta Däubler-Gmelin, who was justice minister at the time, called Maassen's argument, "false, appalling and inhumane."

In 2012, Maassen was tapped to lead Germany's top spy agency. He promised to restore faith in the BfV, which was embroiled in controversy over its entanglement in the right-wing extremist scene and his predecessor's decision to destroy files related to the neo-Nazi NSU murders.

Maassen has been accused of having "a troubled relationship with basic democratic principles" for his pursuit of bloggers on grounds of treason and trying to suppress negative stories on the BfV. In January 2017, he told parliament reports the BfV had undercover agents in the Islamist scene connected to the Berlin Christmas market attack were false. Records showing it did became public in 2018.

Before Maassen made headlines by questioning the veracity of videos of right-wing protesters chasing foreigners through the streets of Chemnitz, he was under fire for advising right-wing populist party Alternative for Germany (AfD) on how to avoid scrutiny from his agency. He has also been accused of sharing confidential documents with the AfD before presenting them to the public.

Interior Minister Horst Seehofer (r.) continued to support Maassen even after his controversial remarks over Chemnitz. Seehofer even took the ex-spy chief into the Interior Ministry in what was essentially a promotion. But that compromise has not been seen favorably by many in Germany, and failed to calm troubled waters within the ruling coalition over the affair.

Maassen was finally forced into retirement in 2018 after he spoke about "radical left-wing elements" in the Social Democratic Party (SPD), the junior partner in the ruling coalition, who had, he said, seized gladly upon his controversial remarks to provoke divisions in the government. He also criticized Germany's policies on refugees and security as "naive and leftist."

The Christian Democrat Union in one district in the eastern German state of Thuringia chose the controversial former intelligence chief to run in this year's parliamentary election. Some 86% of party members in the small region voted in favor of Maassen becoming the party's directly-elected candidate on the ballot. The move means he has a shot at entering Germany's parliament in September.