AUSTIN, Texas — The federal government wants to see Lance Armstrong’s medical records from his treatments for cancer, specifically whether his doctors knew back in 1996 that he was using performance-enhancing drugs.

Court records show that government lawyers subpoenaed the Indiana University School of Medicine on July 30 to provide records of Armstrong’s treatments and donations he later made to the school.

The demand came in the government’s lawsuit to recover millions of dollars in sponsorship money the U.S. Postal Service paid to Armstrong’s teams from 1998-2004. Penalties could approach $100 million.

Armstrong’s lawyers have asked a Washington, D.C., judge to block the subpoena. They called the release of records a violation of privacy and noted Armstrong confessed in 2013 to doping to win the Tour de France seven times. In a deposition given July 23, Armstrong admitted doping before 1996, his lawyers wrote.

“Those documents are irrelevant to the subject matter of this litigation and the request is nothing more than an attempt to harass Armstrong, cause unnecessary delay, and needlessly increase the cost of this litigation,” Armstrong’s lawyers wrote.

The demand for medical records came in a late flurry of government subpoenas for documents and depositions as the case nears the end of the evidence-gathering phase. The government also issued subpoenas last week for testimony from Armstrong’s former sponsors Nike Inc., Trek Bicycle Corp., Giro Sport Design and Discovery Communications Inc., which took over sponsorship of Armstrong’s team in 2005.

Those subpoenas don’t name specific company officials, but allow them to choose a “person most knowledgeable” to discuss sponsorship deals and whether the company had any prior awareness of Armstrong’s doping.

The whistleblower lawsuit was initially filed by former teammate Floyd Landis and was joined by the federal government in 2013..

While Armstrong has confessed to doping since before 1996, the push for medical records and what Armstrong told his doctors could be an attempt to further establish an intricate conspiracy to hide his cheating from federal sponsors.