The University of Minnesota has returned a $50,000 donation at the center of a controversy over the hiring of a DFL state legislator who Republicans alleged received preferential treatment to get the temporary job.

The Minneapolis-based McKnight Foundation confirmed Friday that the donation, part of a larger $433,000 grant package, had been returned.

The U's Institute on the Environment was going to use the money to pay the salary of Rep. Jamie Long, DFL-Minneapolis.

Long, who had accepted a temporary role in July at the Institute's Energy Transition Lab, resigned from the post this week after internal documents sought by House Republicans raised questions about preferential treatment in the hiring process and potential conflicts with his work at the Capitol.

The U solicited the $50,000 gift to establish a "bipartisan fellowship program with two fellows," according to the foundation. McKnight said in a statement that it was not involved in the hiring process and did not know the money would be used to hire Long. The U has since said it will use other funds to pay for the costs associated with Long's hire.

An institute spokeswoman did not immediately respond to a request for comment.