DALLAS (AP) — A prestigious laboratory in Texas is under federal investigation after auditors issued a preliminary report saying it did not do enough to prevent the suffering of primates who were infected with a deadly virus for a study of the disease.

The National Institute of Allergy and Infectious Diseases found a variety of procedural errors with a study conducted at the Galveston National Laboratory, one of the nation's leading research facilities seeking vaccines for some of the most lethal diseases. The lab and inspectors are still discussing the findings before a final decision is issued.

The lab had a contract with the national institute to develop a strain of the Marburg virus that could be used on monkeys to find a cure; all of the monkeys were expected to die. Federal inspectors conducted an audit early this year of the research being done on Macaque monkeys.

The Marburg virus has similarities to Ebola and is among the most virulent pathogens known to infect people, according to the World Health Organization.

The audit found dozens of irregularities, some considered minor and others more serious, from incomplete training files for some employees to data that was not recorded and operating procedures that were not followed. Penalties could range from federal action that ensures compliance, such as additional training for employees, to loss of funding from federal agencies, depending on the final findings.

Lab officials acknowledge minor infractions occurred and say they have been corrected, but they argue the majority of claims, including that animals were allowed to suffer, are unfounded.

"We've disagreed quite strenuously with a number of the findings that were cited," said Toby Boenig, University of Texas Medical Branch vice president and chief compliance officer.

Among the allegations by federal inspectors is that a dozen monkeys infected with Marburg were left unattended for up to 18 hours. The audit contends that leaving them unattended for so long meant researchers missed the opportunity to collect valuable data and resulted in them suffering longer than necessary before death. Eight were found dead in their cages; four others were euthanized.

"It is unknown how long these animals might have suffered before dying," the report notes, later adding, "The clear signs of clinical decline for many of the animals ultimately found dead should have prompted the study director to increase the number of observations in these animals."

The National Institutes of Health's Office of Laboratory Animal Welfare confirmed it's investigating. The federal findings were first reported by The Galveston County Daily News.

The laboratory, part of the University of Texas Medical Branch, opened in 2008. It's one of the few biocontainment facilities in the U.S. licensed to handle the most dangerous pathogens, and the only one operating on a university campus.

Boenig and other administrators said Monday that the lab and federal overseers agreed to a series of protocols outlining the terms of the $2.4 million study. But when federal officials conducted their inspection, they used a different set of protocols, Boenig said.

For instance, inspectors criticized the lab for leaving the Macaques unattended overnight. But Dave Niesel, UTMB chief research officer, said the lab never agreed to such a stipulation, explaining that it is a highly secure facility in which employees often have to wear protective garments similar to a spacesuit. Researchers keep the lights off at night so as not to disrupt the monkeys, so walking in the suits in darkness can be dangerous, he said. Lab officials, meanwhile, say the primates were monitored, including by camera.