Aston University researchers have raised concerns about the number of hours doctoral students are working.
Academics on the university's research committee are worried that postgraduates are taking on more than the recommended maximum of six hours a week paid work to make ends meet.
Research director Graham Hooley said this was the first year the problem had arisen, indicating that postgraduate students were under increasing financial pressure, despite recent increases in research council bursaries.
"Doctoral students are full-time. They do not get the holidays that undergraduates get, so they have less opportunity to make money outside term time.
"Many of them are essentially candidates for academic posts, so we think it is appropriate for them to do teaching support work. But we are worried that more of them are taking on inappropriate work and working longer hours than they should," he said.
Professor Hooley has issued guidelines to research students and their supervisors, suggesting they stick to the recommended six-hour limit.
"When these kinds of issues arise, I worry about our next generation of academics. The levels of bursaries are not high enough to encourage the best to stay on, particularly when the better qualified can quickly be snapped up by industry," he said.
* Aston University's council has voted to postpone moving to the next stage of merger talks with Birmingham University.
The decision follows concerns raised by Aston academics, administrators and students over the basis for a merger.
Aston is seeking clarification from Birmingham on a variety of merger questions.
Birmingham has been given until March 21 to respond, when Aston's council will consider its next step.