In a Securities and Exchange Commission disclosure Tuesday, the medical-device maker, based in Minneapolis, said the U.S. Attorney's Office in Boston subpoenaed information about the study, written by Timothy R. Kuklo.

Dr. Kuklo, formerly on the staff at Walter Reed Army Medical Center in Washington, D.C., retired from the Army in 2007 and joined the faculty at Washington University in St. Louis.

Medtronic, whose bone-growth protein called Infuse was the focus of the Kuklo study, has said it paid him nearly $800,000 over the past three years as a consultant. The company said the payments were for product development and for training other surgeons, and that it had no idea whether Dr. Kuklo did anything wrong.

Dr. Kuklo has declined to comment, and didn't respond to a phone message left at his home.

The study was published in 2008 in Britain in the Journal of Bone & Joint Surgery. That year, the company paid him $249,772. The prior year, when he offered the study to at least two medical journals, Medtronic said it paid him $356,242. In the first few months of 2009, the company paid him $132,453.

Army officials notified the bone journal of its concerns that data were falsified, and the journal retracted the article earlier this year after considering the Army's concerns.

Write to Thomas M. Burton at tom.burton@wsj.com and David Armstrong at david.armstrong@wsj.com

Printed in The Wall Street Journal, page B5