Manhattan U.S. Attorney Preet Bharara said Monday a published report that the city kept his office in the dark about a quashed proposal to demote managers at Rikers Island for providing phony statistics "did not instill confidence" in the city's plan to reform the jail.

In August, Bharara's office issued a report that said adolescents housed at Rikers Island were routinely beaten and had their rights violated. The city has promised to make reforms, but federal prosecutors must decide whether to rely on voluntary efforts or file a lawsuit.

The New York Times reported Sunday that in 2012, city investigators recommended demotion of two managers at Rikers Island because they were inattentive to statistics that misled officials into believing jail fights were on a dramatic downswing.

Instead, former Correction Commissioner Dora Schriro removed the recommendation from the investigative report, and current Commissioner Joseph Ponte promoted the two men to senior positions. The original report was never given to Bharara's office.

"If, as has been reported, incomplete and inaccurate information has been provided to us, and questionable promotions may have occurred, it does not instill confidence in us that the City will quickly meet its constitutional obligations," Bharara said in a statement.

City Comptroller Scott Stringer, in a statement Monday, called for the two correction officials -- Chief of Department William Clemons and Warden Turhan Gumusdere -- to be immediately suspended.

Zachary Carter, the city's top lawyer, did not address Bharara's criticism, but said officials were "committed to complete and expeditious reform" at Rikers Island.