Federal prosecutors in Manhattan have subpoenaed Jeffrey Epstein’s longtime personal pilots, according to people familiar with the matter, as investigators seek to question the financier’s employees in the wake of his indictment on sex-trafficking charges.

The grand jury subpoenas were served on the pilots earlier this month after Mr. Epstein’s arrest on July 6, some of the people said. Mr. Epstein was arrested at Teterboro Airport in New Jersey after he had returned from Paris on a private jet.

A lawyer for one of the pilots confirmed the subpoena, but declined to provide further details.

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This March 28, 2017, file photo, provided by the New York State Sex Offender Registry shows Jeffrey Epstein. (New York State Sex Offender Registry via AP)

It couldn’t be determined what information the subpoenas sought, how many pilots were subpoenaed or whether the pilots have agreed to cooperate with prosecutors.

Testimony from the pilots could be used by federal investigators in their efforts to corroborate accounts from Mr. Epstein’s accusers. They could also provide detail on Mr. Epstein’s travels and his associates. Some of the pilots were responsible for keeping flight logs of passengers who flew on Mr. Epstein’s private jet, according to court filings.

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Mr. Epstein, who was denied bail and will remain in federal custody pending trial, has pleaded not guilty to sex-trafficking charges stemming from what prosecutors allege was a yearslong scheme from 2002 to 2005 to recruit and sexually abuse dozens of girls.

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