MEXICO CITY (Reuters) - The Mexican attorney general’s office said on Sunday a former state governor for President Enrique Pena Nieto’s ruling Institutional Revolutionary Party (PRI) had been arrested at Mexico’s request in Panama on corruption charges.

In a statement, the attorney general’s office said Roberto Borge, 37, who was governor of the state of Quintana Roo until last year, was detained in Panama City airport with the aid of Interpol as he was preparing to board a flight to Paris.

The PRI’s reputation has been battered by graft scandals and Borge’s arrest occurred in the midst of state elections on Sunday that showed the party’s popularity on the slide.

The former governor of the state which is home to tourist resort Cancun had long been accused of corruption by opposition parties, although he has denied the allegations.

The attorney general’s office said a warrant for Borge’s arrest was issued by a Mexican court at the end of May on suspicion he had been handling funds of illicit origin.

In April, former PRI Veracruz governor Javier Duarte, who was one of Borge’s contemporaries in office, was arrested on graft allegations in Guatemala at Mexico’s request.

Duarte is still awaiting extradition from Guatemala.

Preliminary projections on Sunday showed the PRI had narrowly scraped home in an electoral race in one of its main bastions though it appeared to be heading for defeat in at least one other state it has traditionally dominated. [L3N1J229E]