A federal probe into allegations that Sen. Bernie Sanders’ wife fraudulently obtained a nearly $10 million loan for a land expansion at a Vermont college has intensified, with prosecutors reportedly calling a state official to testify before a grand jury.

The federal investigation is focused on actions by Jane Sanders in 2010, when she was president of Burlington College. 

At the time, she sought a multi-million dollar loan for a new campus on 33 acres along Lake Champlain. Sanders reportedly told college trustees and bank lenders that the college had millions of dollars in donations that could be used to repay the loan. 

But The Washington Post reported Monday that trustees said they discovered many of the donors had not agreed to the amounts or the timing of donations listed in materials Mrs. Sanders provided.