Northern Illinois University officials have closed a secret bank account reported to have channeled thousands of dollars to university employees.

NIU employees working at a campus physical plant allegedly sold scrap metal to a company which would write checks to the "coffee fund."

The account contained about $2,100 when closed. It was deposited into NIU's general fund.

University officials say four employees have been placed on paid leave for a month.

Existence of the fund became known when DeKalb Iron and Metal Co. alerted the newspaper. Payment records dating to 2005 show the fund had paid over $13,000.

NIU officials say the money was from a sale of surplus material that was university property. The money was used for social events, like retirement parties.