A high-ranking Richmond police official said yesterday a federal grand jury in Alexandria that has subpoenaed as many as 30 police officers is probing possible sports-related gambling on the city's force.

Maj. Stephen Csaky, head of the Richmond Bureau of Police inspector's office, said that while the department has received no official word on the investigation, "We know what it's about from the complexion of the people asked to appear."

The grand jury panel is expected to hear from officers ranging from patrolmen to captains in two days of testimony scheduled to conclude today.

Csaky said he believed the grand jury's probe is not necessarily restricted to department employes.

Subpeonas were delivered to officers of every rank throughout the department, including the bureau's officers in charge of vice and internal affairs. Those officers said Tuesday they had no idea why they'd been asked to appear before the grand jury.

An earlier police corruption probe by departmental officers and U.S. investigators was disbanded last April amid allegations of misconduct within the special investigative squad. Police Capt. Robert T. Millikin, who headed that squad, has not been subpoenaed and said he does not know the purpose of the grand jury's investigation.

Assistant U.S. Attorney Joseph J. Aronica declined comment yesterday on the grand jury proceedings and if or when indictments would result.