FILE - Former Minister of Social Development Rosario Robles arrives for a hearing on corruption charges at a court in Mexico City, Mexico, Aug. 8, 2019.
FILE - Former Minister of Social Development Rosario Robles arrives for a hearing on corruption charges at a court in Mexico City, Mexico, Aug. 8, 2019.

MEXICO CITY - A Mexican judge has ordered former cabinet minister Rosario Robles detained pending criminal proceedings involving the disappearance of public funds, a lawyer for Robles said Tuesday, in a case hailed by President Andres Manuel Lopez Obrador as part of his campaign against corruption.

Robles served in the cabinet of former President Enrique Pena Nieto from 2012 to 2018, first as secretary of social development and then as secretary of agrarian, land and urban development, and earlier became the first woman to serve as mayor of Mexico City.

Prosecutors have accused Robles of "improper exercise of public service." Robles has appeared in court over prosecution claims that more than 5 billion pesos ($258 million) destined for welfare programs during her tenure had gone missing, according to local media reports.

FILE - Mexico's President Andres Manuel Lopez Obrador attends a news conference at the National Palace in Mexico City, June 10, 2019.

The investigation has fueled accusations that the money was siphoned off, allegations denied by Robles. Julio Hernandez, a lawyer for Robles, said on local television that she will fight the accusations.

"Truly, Rosario Robles is innocent," Hernandez said. 

Lopez Obrador made rooting out corruption a cornerstone of his campaign for the presidency. The investigation into Robles represents one of the highest-profile cases during his administration.

Asked whether the Robles case represented an achievement for his administration, Lopez Obrador said, "I believe that it is an accomplishment that there is no impunity."

Robles is one of several officials from Pena Nieto's administration, including a former head of state oil company Petroleos Mexicanos, or Pemex, to end up in the crosshairs of Lopez Obrador's government. Robles has been a high-profile figure in Mexican politics for two decades. Lopez Obrador succeeded her as mayor of the capital.

During his regular morning news conference, Lopez Obrador said the investigation of Robles will determine whether other people who have served in government are implicated in the case.

Lopez Obrador said that a judge will decide the next steps in the Robles case, stressing the independence of judicial authorities.