The head of domestic intelligence in the city-state of Berlin, Claudia Schmid, resigned Wednesday after an outcry at her agency for shredding files it built up on a neo-Nazi group.

It is the latest in a series of high-profile resignations since the revelation a year ago that a neo-Nazi terrorist group - suspected of being behind a seven-year killing spree of Turkish and Greek immigrants - went unnoticed by the intelligence services.

Schmid, who headed surveillance of neo-Nazis, leftwing and Islamist extremists in the capital, was under fire because her officials shredded files this summer dealing with Blood and Honor, another far-right movement that promotes neo-Nazi rock music.

Her departure was announced by Frank Henkel, interior minister of Berlin, who had said Tuesday the files might have yielded clues about how other neo-Nazis had supported the National Socialist Underground (NSU) trio implicated in the killings of nine immigrants.

Two of the trio died in a murder-suicide in November 2011 and the survivor, Beate Zschaepe, was indicted last week for murder.

Schmid has said the Blood and Honor files were shredded in error, not out of any desire to cover up facts. Among other officials who have stepped down to take responsibility for losing vital files at their offices is a former head of the federal home security service.