Which doctor? John Buse, the University of North Carolina diabetes researcher, who several years ago complained to Glaxo about Avandia risks and marketing. To keep him quiet, Glaxo threatened him with a $4 billion lawsuit.

This became known shortly before Congress held hearings into Avandia last June. Now, The New Scientist reports (subscription required) that written conversations about how to deal with Buse took place at Glaxo’s “highest levels.” Apparently, internal e-mails given to Senate investigators this month show that several execs, including Garnier, Glaxo’s ceo, knew of plans to pressure Buse, according to the mag.

One email, entitled “Avandia Renegade”, was sent in June 1999 by senior vp William Claypool (of the former SmithKline Beecham) to Tachi Yamada, who was Glaxo’s chief scientist, accusing Buse of misrepresenting safety data. Claypool suggested warning Buse not to repeat his remarks, with the “punishment” being that “we would complain up his academic line” and to the bodies that gave Buse accreditation for teaching, the mag writes.

Yamada’s reply, sent the same day, was copied to Garnier, according to the mag. In it, Yamada discusses the possibility of approaching the chairman of Buse’s department and of suing Buse for “knowingly defaming our product.”

New Scientist writes that neither Yamada nor Claypool could be reached for comment, and Buse declined comment. Glaxo spokeswoman Mary Anne Rhyne tells the mag the drugmaker didn’t attempt to silence Buse. “GSK was trying to correct a mistake Dr Buse made in his presentation,” she says. “That was troubling to us and we wanted to make sure that our data was accurately presented. We considered internally a number of options, but ultimately we made our concerns known to Dr. Buse and he corrected his statements.”

Back in June, Buse told The New York Times that the episode was “was upsetting, but it was not life-altering. I hold no ill will toward Glaxo or any of its employees.” Maybe that’s because Glaxo never filed a lawsuit?