New York City Department of Correction Commissioner Joseph Ponte has retired.

His departure comes after weeks of criticism over alleged ethical issues, including using his city-owned SUV to frequently vacation in Maine.

New York City under Ponte's leadership became the first large jail system in the country to ban the use of solitary confinement for inmates under age 22.

However, a report last month by a federal watchdog group found that Rikers Island guards continue to use excessive force at an alarming rate.

Mayor Bill de Blasio released a statement saying: "New York City owes a debt of gratitude to Commissioner Ponte for his tireless efforts to change the culture and improve the effectiveness of one of the nation's most challenging jail systems."