The D.C. police union has asked the District's inspector general to investigate how the department gathers crime statistics, saying that it has uncovered problems in one of the city's busiest police districts.

Union officials said they received a complaint that about 200 crime reports were set aside at the 7th Police District and never counted in crime statistics or were downgraded to lesser offenses. They said they have photocopies of these reports, which allegedly were stashed in a box at the station.

The 7th District covers much of Southeast Washington, and the reports that came to the union's attention involved such crimes as assaults, burglaries, car thefts, minor thefts and attempted thefts, officials said. Most of the crimes had occurred in 2001, 2002 and 2003. Several were from this year; others were from the 1990s.

Union officials said they conducted an audit of the reports and found that some crimes were never entered into databases, according to a letter delivered to Interim Inspector General Austin A. Andersen on Thursday.

The letter urging an investigation was signed by Sgt. Gregory I. Greene, chairman of the D.C. police labor committee of the Fraternal Order of Police Lodge 1. It expressed concern that the department was engaging in a "systematic effort" to misrepresent its crime-fighting success.

D.C. Police Chief Charles H. Ramsey and other police officials dismissed the union's claims, saying the department's crime statistics are thoroughly vetted and reviewed. They said the number of questionable reports was tiny compared with the 800,000 reports taken each year by D.C. officers.

Ramsey also criticized union officials for taking their problems to the inspector general and not presenting them to police commanders.

"If they have a beef, they need to come forward with it officially," the chief said.

Union officials said they went to the inspector general because they wanted an independent investigation. They also gave copies of the reports to The Washington Post, which on Friday provided the department 22 samples to check against the force's database. Police officials said they found 15 in the database. Some other reports may not have been in the database because the crimes were downgraded or unfounded, police officials said.

"We don't think this is a systemic problem," said Nola Joyce, the department's chief administrative officer.

Joyce and Ramsey maintained that the union is raising the issue now because it recently declared an impasse in contract negotiations, sending the talks to a mediator. The union's contract expired last year.

Union officials said that by undercutting the number of crimes, the police department could give citizens a false sense of security. Police have said overall crime is down about 12 percent this year from last year's levels.

Greene said commanders should be held accountable if crimes were not counted.

"People get promoted for favorable crime stats," Greene said.

Assistant Chief Winston Robinson, who was in charge of the 7th District for much of the time in question, said he had no reason to question the statistics.

"I have a lot of confidence in the officers and officials who worked for me while I was commander," Robinson said. "I wouldn't think for an iota of a second that one of those guys would do anything to underreport or not report a crime for any reason."

Police Chief Charles H. Ramsey, left, and Winston Robinson, former commander of the 7th District, say they have confidence in the statistics.