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Federal subpoenas have been served related to the use of public library donations for Irvin Mayfield's New Orleans Jazz Orchestra, multiple sources tell WWL-TV.

The sources spoke on condition of anonymity because the investigation is ongoing.

After WWL-TV aired stories showing that money donated to the New Orleans Public Library Foundation had been routed to the jazz orchestra, NOJO's nonprofit board met this week and voted unanimously to return all of that money to the foundation.

But confirmation of a federal investigation suggests paying the money back may not settle some difficult legal questions.

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