A Philadelphia-based farm-labor contractor failed to pay minimum wages to 125 temporary nursery workers, according to a lawsuit filed against the contractor by the U.S. Department of Labor.

The workers, employed by Heng Heng Agency Inc. and its president, Visith Oum, cultivated nursery stock at Medford Nursery Inc. in Medford, the department said.

A nursery official was unavailable for immediate comment, and a phone number for Heng Heng was inoperative.

"Visith Oum, who has served as the farm labor contractor in this case, has a history of labor law violations and employs vulnerable South Asian and Hispanic workers in the Philadelphia area," said Charlene Rachor, director of the U.S. Labor Department's Southern New Jersey District Office.

Heng Heng is being sued in federal administrative courts for wage and record-keeping violations as well as for violations related to transporting the workers to the nursery.

The Labor Department seeks $146,100 in penalties for willful and repeat violations of the Fair Labor Standards Act and the Migrant and Seasonal Agricultural Worker Protection Act.

Medford Nursery, considered a joint employer, has already paid $36,505 in back wages to the workers, to settle its part of the case. The wholesale company, part of the Robert Baker Cos. in Connecticut, grows roses, rhododendrons, grasses, holly, perennials, and flowering shrubs on 320 acres in Medford.

Hired between December 2010 and December 2012, workers were paid $6.50 an hour, less than the then minimum wage of $7.25 an hour.

Through his South Philadelphia agency, Oum recruited Vietnamese, Cambodian, and Hispanic workers from Camden and Philadelphia, said Steven Risko, assistant district director of the Southern New Jersey office. Some of them were migrant workers, "which makes them even more vulnerable."

Risko said Oum "seems to fly under the radar. We've found him in several states."

The type of temporary contracting agency that Oum runs, Risko said, is becoming more prevalent: "They seem to employ certain segments of the population, and usually it's the immigrant community."

Facts in the case are similar to those that wound up in federal court in New Jersey, where Frank Donio Inc., a Hammonton produce packer and distributor, sued Heng Heng and Oum in August 2012.

In his suit, Donio said U.S. Labor Department investigators informed him that Heng Heng, the agency he used to find temporary labor, was not paying workers properly.

Donio said he paid Heng Heng $9 an hour per worker from 2010 to 2012. According to a 2012 U.S. Department of Labor news release, workers received $6.50 an hour, below New Jersey's minimum wage, then $7.25 an hour.

Donio paid 500 workers $650,000 in back wages to settle the Department of Labor complaint and sued to recover the money from Heng Heng and Oum. After a federal judge awarded Donio $650,000 in a default judgment from Oum, the case was terminated because neither Oum nor Heng Heng showed up in court.