Tucson police have launched an investigation into an allegation of time-card fraud at the Tucson Fire Department.

City officials wouldn’t talk about the open investigation or provide details on how many fire personnel the investigation may involve.

They would confirm only that it is ongoing and that it involves possible discrepancies with “time worked reporting” by some firefighters.

But a city memo showed the investigation began in April after TFD Chief James Critchley learned of problems surrounding how some fire employees were reporting their hours worked.

“The complexity and potential for criminal charges led me to ask TPD to investigate,” Critchley wrote in a memo to the Fire Department on Aug. 3.

Critchley wrote the memo to inform his department that TPD detectives were about to start interviewing Fire Department employees for the investigation.

While interviews were going to be extensive, Critchley said many employees were being interviewed as witnesses, as opposed to suspects.

Critchley said anyone interviewed will be allowed to bring a union or other representative.

A report on the investigation is not anticipated until after police present their findings to the prosecuting attorney, Critchley said.

Since city employees are involved, TPD will likely turn its investigation over to the Arizona Attorney General’s Office or the Pima County Attorney’s Office when it’s completed to avoid any conflicts of interest.

As a result of the investigation, Critchley said policy changes could be in store.

When contacted, Assistant Chief Joe Gulotta said the Fire Department wouldn’t comment because the investigation is ongoing.

Mayor Jonathan Rothschild said if the investigation reveals some type of misconduct, the appropriate action would be meted out.

Although it’s unfortunate that some may have broken the rules, Councilwoman Regina Romero said the city is taking steps to fix it.

“The silver lining is that it is being corrected,” she said.

Contact reporter Darren DaRonco at 573-4243 or ddaronco@tucson.com. Follow on Twitter @DarrenDaRonco