Rancho Feeding Corp., the Bay Area slaughterhouse that recalled nearly 9 million pounds of beef products last month, sold meat that came from cows with cancer, according to documents obtained by the Los Angeles Times.

In a Jan. 14 suspension letter, the U.S. Department of Agriculture’s Food Safety and Inspection Service said that an investigation of Rancho Feeding Corp. showed the company sold cattle "likely affected with epithelioma of the eye."

Regulators said they found two cattle heads that had made it to market intact and with "skin still attached, and had no incisions for the four pair of lymph nodes on the head, which normally are incised for inspection."

The cattle heads did not have the USDA’s mark of condemnation, which would prevent them from being sold, the letter said.

Rancho Feeding is at the center of a massive recall involving thousands of retail chains, including Kroger, Food 4 Less and Wal-Mart, for processing and selling "diseased and unsound animals" without a full federal inspection, the FSIS said.

It has led to voluntary recall by Nestle of its Philly Steak and Cheese flavored Hot Pockets after it discovered a supplier had bought meat from Rancho Feeding.

There are no reported illnesses linked to the company’s meat, but the business is being probed for criminal wrongdoing by the USDA’s inspector general.

The Petaluma, Calif., company has been in regulators’ crosshairs since early January, when it initially recalled nearly 42,000 pounds of beef. That recall was expanded Feb. 8 to include 8.7 million pounds of beef products shipped to distribution centers and retailers in six states including California, Oregon and Texas.

Calls to Rancho Feeding seeking comment Wednesday went unanswered. An e-mail seeking comment from the USDA was not immediately returned either.

Rancho Feeding, the last slaughterhouse in the Bay Area, was recently bought by an artisanal Marin County farm specializing in pasture-raised livestock.

Marin Sun Farms in Point Reyes Station, which is located along a national seashore 40 miles north of San Francisco, has submitted a request to take over Rancho Feeding’s operations, federal inspectors said late last month.

Regulators said they are reviewing Marin Sun Farms’ application to "ensure the firm meets requirements."