Did the Europeans use smallpox against the Indians?

On March 21, 2009, The New York Times reported on Ward Churchill's lawsuit against the University of Colorado. A U of C committee dismissed him from his tenured position for what they found to be very serious acts of academic misconduct such as:

"he had no factual basis for...his theory....that Capt. John Smith purposefully introduced smallpox among the Wampanoag Indians in the 17th century."

Ward Churchill apparently:

"...cited writings of other scholars that he had actually ghostwritten, creating the illusion that there was a body of work supporting his theories."

In Guns, Germs, and Steel: The Fates of Human Societies, author Jared Diamond doubts the Europeans had that sophisticated an understanding of disease transmission. Smallpox, measles, and influenza were introduced during the one hundred years of European contact prior to the time Ward Churchill alleges the Europeans tried to spread disease. Within a few years of these earlier contacts, these disease became a devastating pandemic among the native people who lacked immunity. Almost 90% of them died. Probably nothing the Europeans could have done would made things worse.