Past Firefighter Union President & Oak Lawn Firefighter Robert Lanz being investigated for playing with his man hose while calling phone sex numbers while ON DUTY

An  Oak Lawn fireman who previously served as head of the firefighters union is being investigated for possible on-duty phone sex, officials revealed in court Thursday.

The investigation was revealed during an unusual hearing on a petition for an emergency restraining order filed by firefighter Robert Lanz against the village Tuesday.

In court documents, Oak Lawn officials said they "very recently obtained information that raises very strong concerns that (Lanz) may have engaged in phone sex while on duty on multiple occasions."

Oak Lawn officials then launched an investigation and ordered Lanz to produce his credit card and cell phone records "so that the village could determine whether there was on duty misconduct, and if so the scope and extent of that misconduct," court records show. They also scheduled an interrogation with him for Dec. 18.

"Nobody in the workplace should have to listen to their coworker's sexual conduct," said Benjamin Gehrt, Oak Lawn's attorney.

In court Thursday, Lanz' attorney Patrick Walsh argued that Lanz was given less than two weeks to schedule the interview date and that his union representation wouldn't be available by the deadline.

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