Peru's Justice Minister Gustavo Adrianzen resigned Tuesday, after lawmakers threatened to oust him with a congressional vote.

"Given the current situation, and in a bid to foster the stability our nation's needs, I have submitted my resignation," he said in a brief statement.

Earlier in the day, the authorities published the decree firing Julia Principe, the prosecutor leading the investigation into the financial dealings of the first lady Nadine Heredia. The document was signed by President Ollanta Humala and justice minister Adrianzen.

Principe was probing the suspicious payments that the president's wife allegedly received several years ago. The money, totaling around $215,000 (189,000 euro), was used for her husband's campaign.

The first lady has denied any wrongdoing.

Prosecutor's dismissal

Adrianzen defended the decision to fire Principe, claiming she broke the law by speaking to the media without permission.

"That's the fundamental reason why the decision was made," Adrianzen said. "Following the law is not a technical detail."

At the same time, Principe believes she was fired because her work had made the government "uncomfortable."

Principe is a money-laundering specialist. During her six years in office, she also faced down a major criminal syndicate that trafficked in stolen real estate.

Her latest case involved not only Heredia, but also the ruling Nationalist Party which the president's wife leads.

Ratings for both the party and president Humala have fallen to below 15 percent according to a last week's poll.

Peru is set to hold presidential elections in April 2016.

dj/jm (AFP, Reuters, AP)