By Katie Reilly

NEW YORK (Reuters) - New York City Mayor Bill de Blasio on Monday vowed to push reforms at the city's troubled Rikers Island prison complex after the reported weekend suicide of a 22-year-old man who had been held there for three years without being convicted of a crime.

Kalief Browder was 16 when he was arrested and charged with stealing a backpack, in a case that gained national attention after The New Yorker magazine published a detailed account of the abuse the Bronx teenager endured in jail, during which time he attempted suicide several times.

Browder killed himself on Saturday, the magazine reported, citing his attorney, Paul Prestia. The attorney did not respond to requests for comment on Monday.

Browder maintained his innocence and was released in May 2013 when prosecutors dismissed his case, but he continued to struggle with mental illness, according to the magazine.

"Kalief's story helped inspire our efforts on Rikers Island, where we are working to ensure no New Yorkers spend years in jail waiting for their day in court," de Blasio said in a statement Monday. "There is no reason he should have gone through this ordeal, and his tragic death is a reminder that we must continue to work each day to provide the mental health services so many New Yorkers need."

Rikers Island, one of the largest U.S. jails, which can house up to 15,000 inmates, has gained notoriety over the past year for a culture of violence, including attacks by correction officers on prisoners and the deaths of multiple inmates in custody.

The federal government in December said it would sue New York City after finding widespread violations of teenage inmates' civil rights at the complex, which houses 11,400 prisoners on an average day.

In April, The New Yorker published two videos obtained from Rikers surveillance cameras that showed attacks on Browder by officers and other inmates, fueling the push by politicians and advocates to reform the facility.

(Reporting by Katie Reilly; Editing by Scott Malone and Eric Walsh)