An independent custodial contractor of UC Berkeley is under investigation by the U.S. Department of Labor on allegations of underpaying workers and refusing to pay them for overtime hours.

Since 2008, Performance First Building Services has been under contract to clean the campus’s athletic facilities. Recently, employees of Performance First alleged that the company has avoided paying workers for overtime hours, as first reported by Los Angeles Times.

According to UC Berkeley spokesperson Janet Gilmore, the Department of Labor has advised UC Berkeley that the investigation does not involve the University of California. UC Berkeley is also “independently reviewing the matter,” Gilmore said in an email, and “will respond appropriately” to what it finds.

Department of Labor spokesperson Leo Kay confirmed that an open investigation of Performance First for potential wage violations is being conducted. Kay declined to comment further.

California state law requires that employers pay workers 1.5 times their normal wage after working more than eight hours on a single workday or more than 40 hours in one week. If the allegations against Performance First are proven true, the company would be in violation of these overtime laws.

According to the allegations made by workers, Performance First wrote two paychecks under two different names for one employee to avoid overtime payment and also asked employees to work extra hours without pay entirely. Additionally, employees allege that at times, workers did not receive lunch breaks and worked up to 80- or 90-hour weeks.

Performance First did not respond to repeated requests for comment by phone or email.

Beyond these allegations, the university is facing criticism from some California lawmakers for the unequal benefits and salaries received by UC contracted workers as compared with those of official UC employees. According to a report by American Federation of State, County and Municipal Employees 3299, a union that represents many UC employees, after three years working as a custodian, a contracted worker makes $11.05 an hour, while a UCSF custodian makes $17.01 an hour.

According to Gilmore, the campus’s contract with Performance First does not specify a pay rate, and the company is not required to inform UC Berkeley of the salary it pays its employees.

“Unless the terms of a contract specify at what rate workers must be paid, this is information that is kept between the contractor and the workers it hires,” Gilmore said in an email.

Gilmore also noted that under the UC Fair Wage/Fair Work Plan, which went into effect Thursday, contracted companies are required to pay workers at least the UC minimum wage.

In September, the state Legislature passed Senate Bill 376, which would require “a total employee compensation package” for contracted workers comparable with that of employees of the UC system.