MEXICO CITY (AP) — A Mexican official's use of a government helicopter for personal transportation sparked calls for his resignation and an investigation of possible abuse of office Thursday.

The Public Administration Department, Mexico's anti-corruption agency, said in a statement that it was probing the incident, the latest in a string of recent scandals reaching the highest levels of government.

The uproar began with photos published online showing several people walking from an SUV toward a helicopter emblazoned with "Conagua," the acronym of Mexico's National Water Commission.

Although the faces were not clear in the pictures, some Mexican news outlets and social media identified the people as Conagua director David Korenfeld and family members. The photos were said to have been taken by a neighbor.

Through his Twitter account, Korenfeld acknowledged and apologized for using the helicopter. He said he was reimbursing the government for the cost of the flight, but did not disclose how much that was.

"I made an inexcusable error by using a Conagua helicopter to transport myself to the AICM," or Mexico City International Airport, Korenfeld tweeted. "For that, I offer a public apology."

Critics nevertheless called for him to step down.

Sen. Javier Lozano of the conservative opposition National Action Party tweeted that the incident "merits the resignation of the person who made the mistake."

Columnist Julio Hernandez Lopez wrote in the left-leaning newspaper La Jornada that Korenfeld was "caught in a flagrant abuse of power."

Abuse of power, corruption and favoritism are longtime complaints in Mexico, and the current government has not been exempt from allegations of impropriety.

President Enrique Pena Nieto, his wife and the Treasury Department secretary came under fire last year over the purchase of luxury homes from government contractors, though they denied any wrongdoing or conflict of interest.

In 2013, shortly after taking office, Pena Nieto fired the head of Mexico's consumer protection agency after the official's daughter tried to have inspectors shut down a restaurant that didn't give her the table she wanted.