LOS ANGELES (CBSLA.com/AP) — City officials say a new audit has uncovered “staggering” evidence of possible overtime fraud by workers at the Los Angeles Department of Transportation (DOT).

City Controller Ron Galperin released a report Tuesday showing workers in the DOT’s Traffic Paint and Sign Section billed an average of $48,100 in overtime in fiscal 2013-14, compared with about $8,300 in many other city departments, according to Associated Press.

READ MORE: 3 Gang Members Arrested In Beverly Hills Restaurant Shooting

The audit found nearly half of 67 employees in the division claimed more than 1,000 hours of overtime, while another 30 claimed at least 2,000 hours of overtime – all on top of their regular work schedule.

13 of 67 workers logged 40 hours of overtime per week, with one employee claiming to have worked 16 to 18 hours per day for two weeks.

All told, Traffic Paint and Sign employee overtime cost taxpayers $3.3 million dollars in fiscal year 2013-14, according to the audit.

Galperin told KNX 1070 NEWSRADIO the report – which was triggered by a tip at the DOT’s fraud hotline – revealed some “disturbing numbers”.

READ MORE: Adrian Gudino Wanted In Redondo Beach Murder Of 68-Year-Old Relative, Gloria Pressett

“We had one superintendent who was receiving $155,000 in overtime on top of his $78,000 salary,” said Galperin. “There’s a certain point at which it seems nearly impossible that somebody could work so many hours, for such an extended period of time, without completely breaking down.”

A previous audit conducted by Galperin’s office found L.A. firefighters were paid an average of $43,000 in overtime pay.

The Controller’s findings examined the period prior to when Seleta Reynolds took over as DOT General Manager.

In a statement, Reynolds indicated her administration has reviewed and accepted the audit and recommendations, including plans to create an online overtime request and approval system and to “right-size” the DOT’s overtime budget.

“Integrity and accountability are core values in our Strategic Plan, and we intend to meet the public’s expectation for delivering service in a fiscally responsible way,” said Reynolds.

MORE NEWS: Gas Prices In Southern California Keep Ticking Up, But Cyberattack On East Coast Pipeline Not Expected To Make An Impact

(TM and © Copyright 2015 CBS Local Media, a division of CBS Radio Inc. and its relevant subsidiaries. CBS RADIO and EYE Logo TM and Copyright 2015 CBS Broadcasting Inc. Used under license. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed. The Associated Press contributed to this report.)