DENVER — A Colorado cantaloupe grower who was implicated following an outbreak of listeria that killed 30 people last year was fined by the U.S. Department of Labor on Thursday for failing to provide safe migrant worker housing.

The federal agency said grower Eric Jensen rented migrant workers unsanitary, overcrowded rooms at a motel he owns. Inspectors said many rooms lacked beds, laundry facilities and smoke detectors. Jensen faces $4,250 in civil penalties. The fine was not linked to the outbreak.

“Profiting at the expense of vulnerable workers is not just inhumane, it’s illegal,” said Chad Frasier, the Wage and Hour Division’s district director in Denver.

Jensen said Thursday the fine was unwarranted. He said he didn’t know the people who rented the rooms for a month were migrant workers.

“It was closed at the time, and they wanted to rent it,” Jensen said. He said he didn’t know he had to verify their employment.

The outbreak of listeria in cantaloupe last fall was the deadliest outbreak of foodborne illness in 25 years. Thirty people died, 146 people were sickened and one woman suffered a miscarriage after eating tainted cantaloupe, according to the federal Centers for Disease Control and Prevention.

The Food and Drug Administration said in October that pools of dirty water on the floor and old, hard-to-clean equipment at Holly, Colo.-based Jensen Farms probably were to blame.

Government investigators found several positive samples of listeria bacteria on equipment in the Jensen Farms packing facility and on fruit that had been held there.

The farm also had stopped using antibacterial washes and did not “pre-cool” cantaloupes off the fields to reduce bacteria growth, the FDA said.

Jensen Farms recalled the cantaloupes in September.

An investigation is ongoing, authorities have said.

Jensen faces multiple lawsuits related to the outbreak.

FILE – In this Sept. 28, 2011, file photo, cantaloupes rot in the afternoon heat on a field on the Jensen Farms near Holly, Colo. Pools of water on the floor and old, hard-to-clean equipment at the farm’s cantaloupe-packing facility were probably to blame for the deadliest outbreak of foodborne illness in 25 years, the Food and Drug Administration said Wednesday, Oct. 19, 2011. Government investigators found positive samples of listeria bacteria on equipment in the Jensen Farms packing facility and on fruit that had been held there. Photo by ED ANDRIESKI, THE ASSOCIATED PRESS