For the last four years a growing movement of Harvard medical students has been working to expose and limit pharmaceutical companies’ influence on their university. 

So they were perturbed, to say the least, when they discovered a representative of the giant drug company Pfizer photographing students participating in an on-campus demonstration on the issue last fall.

Pfizer admits that the photographer was one of their employees, but refuses to release the man’s name, and contends, as the New York Times paraphrased their statement, that he “photographed the students for personal use.”

At least 149 Harvard medical school faculty are on the Pfizer payroll in one way or another, and the company finances two research projects and a continuing medical education program on campus. In addition, Pfizer made donations of $350,000 to the medical school last year.

The pharmaceutical industry is already the subject of a Senate investigation of their influence on American medical schools, and yesterday Iowa Senator Chuck Grassley sent Pfizer a letter saying he was “greatly disturbed” by the the incident, which, he said, “raise[s] concerns that Pfizer is attempting to intimidate young scholars from professing their independent views on issues that they think are critical to science, medicine, and the health and welfare of American taxpayers.”

Grassley asked Pfizer to provide him with an accounting of all payments the company made to Harvard medical faculty since the beginning of 2007, and of all corporate “communications [including photos] regarding Harvard medical students demonstrating and/or agitating against pharmaceutical influence in medicine” since the beginning of 2008.

He gave them a one-week deadline to respond, and a Pfizer representative said on Tuesday that it would “fully cooperate with Senator Grassley’s request for information.”