Mr Breuer is accused of bankrupting a prominent media organisation whilst head of the Frankfurt-based bank, although now prosecutors have decided that allegations of breach of trust should also be considered.
The case relates to the collapse of Kirch Media Group, which Deutsche Bank had a contractual relationship with.
The group's owner Leo Kirch alleges that comments made by Mr Breuer in a television interview regarding the company led to the withdrawal of financial backing, causing the company to collapse.
Now prosecutors say that after an exchange of letters with Mr Kirch's lawyers, they will also consider the charge that Mr Breuer also breached the trust of Deutsche Bank in making the remarks.
Lawyers acting for Mr Breuer called the move "incomprehensible", saying that there had never been any proof that Breuer had set out to harm Deutsche Bank in the interview.