Now, all of the cases it investigates must involve bribes of more than 10,000 euros, around $12,500, and state employees above a certain level.

Romania’s Parliament has repeatedly tried to limit anticorruption efforts, with legislators complaining that they are being targeted for political reasons and proposing an amnesty law, a move Ms. Kovesi said she strongly opposed.

The mingling of politics with both corruption and the fight against it has become a particularly heated issue in recent weeks amid a presidential election, the second round of which will be held on Sunday. The vote will decide who replaces the current center-right president, Traian Basescu, who appointed Ms. Kovesi in May 2013. Mr. Basescu’s opponents saw the appointment as a move to ratchet up pressure on the Social Democratic Party of Victor Ponta, the center-left prime minister and the front-runner in the presidential election.

“Of course, there are lots of statements that we conduct political cases,” Ms. Kovesi said. “My answer is that we don’t open political cases.” She noted that her agency had brought corruption charges against members of many parties, not just Mr. Ponta’s, and had also jailed Mr. Basescu’s brother for taking money from a crime boss.

A CAREER prosecutor whose father was also a prosecutor, Ms. Kovesi studied law in the northwestern city of Cluj. After graduating in 1995, she took the first in a series of jobs in a Romanian justice system that the European Commission has regularly assailed as skewed by political interference and corruption. But despite much digging by her opponents, no solid evidence has come to light of any wrongdoing on her part.

The author of many articles on arcane legal issues and a recipient of commendations from the United States, Ms. Kovesi keeps a wall around her personal political views, avoiding the emotional hyperbole that often dominates public discourse in Romania in favor of clipped legalese.

Since Ms. Kovesi took over D.N.A. last year, what was a trickle of high-profile arrests and prosecutions has become a flood. Nearly all have ended in convictions, with her prosecutors recording a success rate of over 90 percent.