CHICAGO (CBS/AP) — U.S. Rep. Jesse Jackson is taking a medical leave of absence and is being treated for exhaustion.

The congressman’s office made the announcement in a three-sentence statement Monday afternoon. The office did not say how long Jackson would be away. It said his office remain open for constituent services.

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He began his leave about two weeks ago, but announced it Monday. He has missed several House votes in that time.

Jackson first won office in 1995 and represents Illinois’ 2nd District, which includes Chicago’s South Side and the city’s southern suburbs. He is under investigation by the House Ethics Committee.

Jackson faces allegations that he was involved in discussions about raising money for then-Illinois Gov. Rod Blagojevich’s campaign in exchange for an appointment to President Barack Obama’s old Senate seat.

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The announcement comes a week after former Jackson fundraiser Raghuveer Nayak was indicted on federal fraud charges.  Nayak was at the center of the Blagojevich-Jackson allegations, but the indictment was related to Nayak’s medical clinics.

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