Eleanor Wright of Fisher Meredith Solicitors said her client had suffered a nervous breakdown as a result of workplace bullying and was still receiving treatment, but had agreed to take part in a postgraduate study into the area.
But Wright's client claims the project went ahead without being referred to the university's ethics committee, which was obliged to ensure that anyone taking part in the research would not be adversely affected.
The man also claims he was not advised to consult his doctor before participating.
"He was asked to revisit the causes of his breakdown, which could be dangerous," said Wright. "And so far as we know nobody ever asked him to stop and think about what was going on. My client wants a proper investigation and an acknowledgement that [the project] did go wrong."
Staffordshire University's law firm Martineau Johnson was unavailable for comment.