A government spokeswoman said Ms Schmidt had asked a Hamburg lawyer to take care of her interests.

German newspapers at the weekend reported that Ms Schmidt had worked in a bar in the red-light district in Aachen and had been involved in a casino, which was investigated for tax irregularities.

Ms Schmidt, who was only appointed to the German cabinet last week, is one of a number of ministers under media pressure over alleged misdemeanours.

On Tuesday, Foreign Minister Joschka Fischer, who has faced calls to resign after revelations of a violent past in radical politics, will testify in the trial of Hans-Joachim Klein, accused of assisting the convicted terrorist Carlos the Jackal.

Single mother

Chancellor Schroeder is reported to have voiced his support for his latest appointee, telling Ms Schmidt, "Don't worry, we'll get through this together."

Newspaper reports revealed Ms Schmidt had worked as a waitress in her sister's bar in the red-light district of Aachen, where a police raid confiscated pornographic videos.

Ms Schmidt responded in Spiegel magazine saying, "I was a student and single mother and had to earn money. So I was happy that I could work as a waitress at my sister's place once a week."

She was also implicated in a tax raid on her sister's gambling club but has denied allegations of money laundering.

Violent past

Mr Schroeder has also been shoring up his beleaguered Foreign Minister, Joschka Fischer, who will testify on Tuesday at the trial of Hans-Joachim Klein, an acquaintance from his days in radical politics in the 1970s.