At least some of the long-time personal pilots for global jet-setting and accused child sex trafficker Jeffrey Epstein have been subpoenaed by federal prosecutors as investigators scrutinize the convicted sex offender’s travels, according to a report.

A Manhattan grand jury sent Epstein’s pilots subpoenas earlier this month, the Wall Street Journal reported Friday. One pilot’s attorney confirming that the subpoena had been issued.

It isn’t clear which pilots were subpoenaed, what topics the subpoenas cover, and whether any of the pilots are working with investigators already. Epstein, who has homes in New York City, Florida, New Mexico, and the Virgin Islands, was arrested at Teterboro Airport in New Jersey earlier this month when he arrived from Paris, France, where he also has a residence.

Epstein allegedly sexually exploited and abused dozens of minor girls at his homes and other locations between 2002 and 2005 and perhaps beyond. Some of the victims were reportedly as young as 14 at the time the alleged crimes occurred.

Government attorneys said Thursday they are willing to give documents and materials — including what they said were “highly confidential images of nude or partially-nude individuals” that they’d seized during their raid of Epstein's Manhattan home earlier this month — to Epstein's attorneys but that the premature release of this evidence to the larger public “would impede the government’s ongoing investigation of uncharged individuals.”

Local police in Palm Beach, Florida and federal prosecutors first looked into Epstein's travels in 2005, but that halted in 2008 when Epstein’s lawyers and federal prosecutors, led by then-U.S. Attorney Alex Acosta, reached a nonprosecution agreement. Acosta resigned as secretary of labor over questions into the sweetheart deal.

Under the deal, Epstein pleaded guilty to two state-level prostitution solicitation charges and served just 13 months of his 18-month sentence at a Palm Beach County jail where he was allowed out on work release. Epstein paid some restitution to certain victims, and eventually registered as a sex offender.

Larry Visoski, the longtime chief pilot of Epstein’s fleet of helicopters and planes, Larry Morrison, David Rodgers, and Bill Hammond have been named as Epstein’s pilots and flight engineers in a number of court documents. Visoski and Morrison were deposed as part of lawsuits brought by alleged victims in the wake of the 2008 deal. Those lawsuits also spurred the release of flight manifests signed by Rogers showing Epstein crisscrossed the globe from 1997 to 2005 accompanied by tycoons, celebrities, employees, friends, and politicos, including former President Bill Clinton.

Some of Epstein's alleged victims have said the logs show they were on Epstein’s so-called “Lolita Express” when they were underage, and that Epstein’s pilots and other employees helped him break the law in the late 1990s and early 2000s. One Epstein accuser has said that she was a minor in 2000 when she would would accompany Epstein on his jet, where she alleges that she was sexually abused by some of Epstein’s pals.

Epstein is in jail after a judge last week denied him bail.