The New York City Police Department is frustrating the City Council’s efforts to oversee police stop-and-frisk procedures by refusing to give lawmakers an electronic database to track the practice among police, the council speaker said yesterday.

The department has already given the council data on police searches from 2006 in four volumes totaling 1,200 pages and hired a think tank, the Rand Corporation, to conduct an independent study of police searches of civilians. Still, Speaker Christine Quinn, supported by the New York Civil Liberties Union, criticized the NYPD for denying the council detailed information about individual stops in a more usable electronic format.

“We have expressed our disappointment with the NYPD about their unsatisfactory response in providing the needed data,” Ms. Quinn said. “If they continue to fail to provide the numbers, we will take the appropriate action and get the information we need to conduct the oversight that is mandated by the charter.”

An NYPD spokesman, Deputy Commissioner Paul Browne, said the department has “already provided reports on the data to the City Council, as required by law.” A law enacted after police fatally shot an unarmed black man, Amadou Diallo, in 1999, requires the NYPD to submit data on police searches of civilians to the City Council for oversight.

Last year, the NYPD released a report showing that in 2006 police had stopped 508,540 people for searches, up from about 97,000 in 2002, the last time police released a full year’s worth of data. Without the electronic database, NYCLU and City Council sources said they had an incomplete picture of the stop-and-frisk data, which they are interested in analyzing to see whether police are engaging in unconstitutional racial profiling. More than half of those stopped in 2006 were black.

“In terms of race, the data showed that stops were consistent proportionately with descriptions provided by victims of violent crime,” Mr. Browne said.