NEW YORK - A college that had its most high-profile moment earlier this year when first lady Michelle Obama gave a commencement address is now grappling with its president's abrupt resignation amid questions over the handling of her personal expenses and a call for a state investigation.

Lisa Coico, who had been City College of New York's president since 2010, resigned Friday, a day after The New York Times asked questions about how $150,000 in her expenses had been documented. Neither she, nor the chancellor of the City University of New York system of which City College is a part, gave a reason for her departure.

The Times had raised questions earlier this year about Coico's personal spending in 2011 and about how a foundation that fundraised for City College had paid thousands of dollars in Coico's expenses including housekeeping, furniture and food and was in turn reimbursed by another CUNY foundation that oversees research funds for the entire system. A few weeks after that story came out, the U.S. attorney for the Eastern District of New York issued a federal subpoena as part of an investigation into the matter.

The Times said its most recent questions on the subject on Thursday had concerned whether an internal memo on the reimbursements was genuine and, separately, whether Coico had paid back a $20,000 security deposit on a rental home.

In announcing Coico's resignation, CUNY Chancellor James Milliken declined to give any specifics beyond naming an interim administrator in charge pending the appointment of an interim president later in October. He said a national search for a new president would be undertaken and called City College "a remarkable institution with a rich history and a very promising future."

The situation spurred the chairman of CUNY's board of trustees, William Thompson Jr., to send a letter to the state on Sunday, asking the inspector general to look into all of the schools in the CUNY system and their affiliated foundations.

CUNY is New York's public university system, made up of senior colleges, community colleges and graduate schools throughout the city's five boroughs. City College, in Manhattan, was founded in 1847 as the Free Academy of the City of New York and became the flagship school in the CUNY system.

In the 1930s, Jewish intellectuals kept out of elite private colleges were educated there, giving it the reputation of the poor man's Harvard University. Among its alumni are 10 Nobel Prize winners.

In June, Obama, the wife of Democratic President Barack Obama, picked the school to give her last commencement address as first lady. She said she chose it because of its diversity, with its students coming from 150 countries and speaking more than 100 languages.

"You represent just about every possible background," Obama told the graduates, "every colour and culture, every faith and walk of life."

In the speech, Obama took a mild swipe at Donald Trump, who at the time was the presumptive Republican presidential nominee, by saying that "some folks" don't value diversity but that America doesn't "build up walls to keep people out."

Trump, the GOP presidential nominee, has promised to build a wall between the United States and Mexico, proposed banning Muslims from entering the U.S. and said it's risky to take in Syrian refugees because terrorists could be among them.

News from © The Associated Press, 2016