TACOMA, Wash. -- A whistleblower claims the city of Tacoma paid its police officers to play basketball, according to a complaint filed with the Tacoma Police Department.

The complaint prompted the department's internal affairs office to launch an investigation into a practice that may have been going on for several years.

Once a year, Tacoma police and firefighters square off on the basketball court to raise money for the Hilltop Action Coalition, an alliance of 72 block groups that work to promote a community free of illegal drugs and gang activity.

The complaint claims those police officers were paid to play in the game, which have become an annual tradition. In the weeks leading up to the game, the complaint alleges, the officers were even getting paid to practice.

The whistleblower states police officers were paid for a full ten-hour shift even though the charity game only lasted two or three hours. The state's probationary officers were allowed to play instead of attending training shifts, the whistleblower wrote, and additional officers had to be called in to cover shifts for the basketball players.

The city manager's office got involved in the investigation when the complaint was filed on June 1.

"We take it seriously. That's why we want to hear about it. We have a very public process," said Tacoma community relations manager Rob McNair-Huff.

The investigation is being conducted by the police department, but the city manager will have the final say.

"We'll see what comes out of this investigation," McNair-Huff said. "If there are further questions, I'm sure that they will be asked and answered."

Tacoma police spokesman Mark Fulghum says Police Chief Don Ramsdell has ordered the basketball practice to stop immediately. But he added the department doesn't know yet how many officers may have been involved or how much the games have cost taxpayers.

Tacoma fire officials claim they typically do not pay for firefighters to play or practice for off-duty events like the charity basketball game. But the officials said they did make an exception in the case of one firefighter because the charity game fell on his work day.