BY FRANCES ROBLES

The former chief of Cuba's military medical services is calling for international weapons inspections of a secret underground lab near Havana, where he says the government is creating biological warfare agents like the plague, botulism and yellow fever.

Roberto Ortega, a former army colonel who ran the military's medical services from 1984 to 1994, defected in 2003 and now lives in South Florida.

After living here quietly for four years, this week Ortega went on the Spanish-language media circuit to denounce what he claims is an advanced offensive biological warfare weapons program. He spoke Tuesday night at the University of Miami's Institute for Cuban and Cuban-American Studies where one angry heckler stormed out accusing him of deliberately sowing fear among Cuban exiles.

''They can develop viruses and bacteria and dangerous sicknesses that are currently unknown and difficult to diagnose,'' Ortega told The Miami Herald. ``They don't need missiles or troops. They need four agents, like the people from al Qaeda or the Taliban, who contaminate water, air conditioning or heating systems.''

He said Cuba was ready to use the biological agents ''to blackmail the United States in case of an international incident'' such as the threat of a U.S. invasion.

The Cuban government has denied such programs exist, but if Ortega's allegations are true Washington could face the prospect of an enemy nation 90 miles away with the capability of launching germ attacks.

UNDERGROUND LAB

Ortega said he told the CIA nearly two years ago about an underground Cuban facility southwest of Havana. The maximum security lab dubbed ''Labor One'' has an above-ground civilian cover and employs dozens of scientists, he said.

But in the underground facility, scientists reproduced and stockpiled deadly germs and bacterias collected in Africa, he added.

He visited the lab in 1992 when he accompanied a high-level Russian military delegation, he said.

''I saw it,'' Ortega said. ``I lived it.''

Ortega is believed to be the first defector with details of such an alleged biological warfare facility, said University of Miami professor Manuel Cereijo, who studies Cuba's biotechnology and terrorism issues.

Ortega said he has come forward now because he did not see the CIA taking public action on his information. The CIA and the U.S. State Department declined to comment.

''He talks about a place I never heard about,'' Cereijo said. ``There are many other places where there exists the capacity to develop bioweapons. That doesn't mean they are doing that. Only a person like him would know.''

ADVANCES KNOWN

Cuba's advanced biotechnology industry is well-known, having produced vaccines for hepatitis and meningitis B and exported them to dozens of countries around the world. In 2002, John Bolton, then a top U.S. State Department official for arms control, said Cuba ``has at least a limited offensive biological warfare research and development effort.''

In a report last year, the State Department acknowledged analysts were divided on the issue of whether Cuba has such a program. Experts also argue that the U.S. government is unlikely to have high-level spies in Cuba feeding it information on what must be, if it exists, a highly secret program.

Ken Alibek, former deputy director of the Soviet Union's bioweapons program, said Russian scientists always suspected the Cubans were developing a biological warfare program, but said he doubts that any Soviet military delegation would have been invited to visit it.

''If you ask whether the Cubans are capable, I'd say easily,'' he told The Miami Herald in a telephone interview from Virginia. ``Are they doing it? I can tell you when I was involved in the late 80s, we suspected so.''