Mexico's top electoral crimes prosecutor says federal officials will take over the investigation into a former governor who allegedly channeled state funds to the ruling party.

Hector Diaz-Santana said Monday he expects state officials to turn over case files related to Cesar Duarte, the former governor of the northern border state of Chihuahua.

Chihuahua's opposition governor Javier Corral has accused Duarte of diverting public money to the 2016 electoral campaign of President Enrique Pena Nieto's Institutional Revolutionary Party.

Corral has also accused officials of dragging their feet on the case and has staged a series of marches to demand prosecution and force the federal government to pay money it has promised the state.

Federal prosecutors have already filed extradition requests for Duarte, who is believed to be in the U.S.