The medical device maker indicated in a filing with the Securities and Exchange Commission that it had received a subpoena on May 21 from the United States attorney in Boston seeking information about its financial ties and other dealings with Dr. Timothy R. Kuklo, a former orthopedic surgeon at Walter Reed Army Medical Center in Washington.

Steven Cragle, a Medtronic spokesman, said that the company had no comment on the subpoena beyond its S.E.C. filing. Dr. Kuklo, who is currently an associate professor of medicine at Washington University in St. Louis, has repeatedly declined to comment on the episode.

Last week, Medtronic, at the behest of Senator Charles E. Grassley, Republican of Iowa, disclosed that it had paid about $800,000 in consulting fees over the years to Dr. Kuklo, with the vast bulk of those funds paid to him in the last three years.

It was over that period that Dr. Kuklo submitted his now-challenged Infuse study to a series of medical journals before it was published last August in the British edition of The Journal of Bone and Joint Surgery. It claimed Infuse performed "strikingly" better than a traditional bone graft when used to repair serious leg injuries suffered by American combat soldiers in Iraq.

In an investigation completed last year, the Army accused the orthopedist of forging the name of other military doctors on that Infuse article and citing patient data that did not match Walter Reed records.

For Medtronic, the Justice Department subpoena represents a new stage in a deepening quandary involving Dr. Kuklo.

While Medtronic's chief executive, William A. Hawkins, was formally informed of the Army's findings on Dec. 31, the company continued to pay Dr. Kuklo tens of thousands of dollars in fees and continued to have him speak to other doctors about Infuse.

The company suspended his consulting contract last month after The New York Times published an article in early May detailing the Army's findings and after Senator Grassley began seeking data about Medtronic's financial ties to the physician.
Earlier this week, Mr. Cragle, the Medtronic spokesman, declined to say when Medtronic first learned of the allegations against Dr. Kuklo.

The new subpoena comes as the Justice Department and Senator Grassley continue to investigate whether Medtronic violated any federal rules by promoting unapproved uses of Infuse, a charge that the company denies.

Dr. Kuklo became a Medtronic consultant in August 2006, the month that he left Walter Reed, though he did not formally retire from the Army until months later.

While Medtronic's filing did not cite Dr. Kuklo by name, it did make reference to a Justice Department request for documents related to a retracted article in the British medical journal. According to the filing, the department requested "contracts, research grants, speaking and education programs, and payments for certain named physicians" involved in the study reported in the British journal.

Dr. Kuklo is the only person associated with that report accused of any wrongdoing.