Leaky equipment and faulty pasteurization were found at a plant that made contaminated cheese linked to the deaths of 42 people since mid-March, officials said yesterday.

As inspections for the bacteria-tainted cheese were planned or conducted in 24 states, preliminary tests showed pinholes in pasteurization equipment at the Artesia plant of Jalisco Mexican Products Inc., a state Food and Agriculture Department spokesman said.

"Anytime you have pinholes you have the possibility of contamination, because raw milk could make contact with hot milk," Jan Wessell said.

Other tests found phosphatase, an enzyme normally deactivated by pasteurization, in product samples, she said.

Those results contradicted state findings last week that the plant's pasteurization had been cleared of blame. However, federal and local officials had challenged those findings as premature.

The Food and Drug Administration is to fly a pasteurization engineer here this weekend to confirm the dye tests that found the pinholes and to do additional checks on the pasteurization unit, Wessell said.

Of the 42 people killed by Listeria monocytogenes bacteria thought to come from Jalisco products, 25 lived in Los Angeles County and 15 lived elsewhere in California. One listeriosis death in Arizona and one in Texas have been blamed on the cheese.

The Jalisco plant has been closed and most of its more than 100 employes laid off.

Inspections for tainted cheese were being conducted in Arizona, Arkansas, California, Colorado, Florida, Georgia, Hawaii, Idaho, Kansas, Louisiana, Massachusetts, Michigan, Nevada, New Jersey, New Mexico, New York, North Carolina, Oklahoma, Oregon, Rhode Island, South Carolina, Tennessee, Texas and Washington state.