Language was attached to last year's budget that requires the university to inform the legislature how many stem cell lines it has created and has on hand as well as numbers of embryos and research projects.
Lawmakers on a subcommittee dealing with the issue accused university officials of "thumbing their nose" at the Legislature, the Detroit Free Press reported.
They have said the university could be stripped of some state aid.
"If we roll over, I think it will have a precedent effect, and we'd be really weakening the power of the Legislature," said state Rep. Kevin Cotter, a Republican from Mount Pleasant.
The university is the only one in the state involved in stem cell research. President Mary Sue Coleman said the university sent 50 to 60 pages of information on stem cell research because officials wanted to put the numbers in context. But legislators complain the specific numbers the university is required to give were not there.
"We believe it's just not possible to boil down this incredibly important work to a series of data points," said Rick Fitzgerald, a university spokesman. "We are emphatic about putting our stem-cell research in the context of its potential to cure diseases and save lives. That's what we did when we provided a bit more information than what the Legislature sought."