Dr. Joseph Biederman, of Harvard Medical School, is a world-renowned child psychiatrist whose work has helped fuel an explosion in the use of powerful antipsychotic medicines in children. He earned at least $1.6 million in consulting fees from drug makers from 2000 to 2007. However, he did not report much of this income to university officials.

Biederman and other researchers may have violated federal and university research rules designed to police potential conflicts of interest.

Dr. Biederman reported no income from Johnson & Johnson for 2001 in a disclosure report filed with the university. When asked to check again, he said he received $3,500. But Johnson & Johnson said that it paid him $58,169 in 2001.

Biederman’s consulting arrangements with drug makers were already controversial because of his advocacy of unapproved uses of psychiatric medicines in children.