PORTLAND – Workers at a poultry-packing plant have filed a lawsuit in federal court accusing the locally owned company of making them perform tasks for which they are not paid.

The suit in U.S. District Court claims Barber Foods violated the Fair Labor Standards Act. The case covers only three years because the statute of limitations blocks claims for previous years.

Barber has 750 full-time employees and 44 percent of them came to Maine from other countries.

Four employees are named as plaintiffs in the case, which could eventually include hundreds of workers. At stake are millions of dollars worth of back wages.

A Barber Foods spokeswoman said the company is investigating the allegations.

“We pride ourselves in treating all our employees fairly,” said Vicki Mann, adding that the company provides services to its workers, such as onsite classrooms in which English, math, science and computer skills are taught.

Worker advocates said the company is taking advantage of employees who don’t speak English well and don’t understand their rights. The suit accuses Barber of failing to record and pay for all of the time it requires or permits its employees to work.

“I think people are fed up with how they are being treated,” said Kathy Poulos, a Portland advocate for refugee and immigrant rights. “We want these procedures to be revised and to come into compliance with the law. We want people paid for the hours they work.”

Barber Foods was founded in 1955 by Gus Barber and is still owned by the Barber family. It offers a wide variety of products, including frozen chicken entrees. It distributes to grocery stores, restaurants and other businesses throughout the United States and Canada as well as some other foreign markets.