“I want to get to the bottom of what happened at Rivington, St. Nicholas and other sites,” said Councilman Ben Kallos, an Upper East Side Democrat whose committee oversees the Citywide Administrative Services Department, which grants deed restrictions. “The Council has a responsibility to hold an oversight hearing on deed restrictions.”

In preparation for a hearing, the de Blasio administration on June 15 released to Ms. Mark-Viverito’s office a list of 14 properties around the city that it said had pending applications for deed modifications or removals when the Rivington House deal came to light. The city halted new deed changes shortly after.