There is no credible, publicly available evidence confirming that Jeffrey Epstein was an FBI asset or informant between 2003 and 2009.
Epstein confirmed as FBI asset & informant between 2003-2009

Jeffrey Epstein client list - Wikipedia
Source: en.wikipedia.org
Key Evidence
Wikipedia entries on Jeffrey Epstein and related topics do not confirm any FBI asset or informant status for Epstein.
en.wikipedia.orgen.wikipedia.orgJeffrey Epstein client list
en.wikipedia.orgen.wikipedia.orgDeath of Jeffrey Epstein
en.wikipedia.orgen.wikipedia.orgJeffrey Epstein
Investigations into Epstein’s death and criminal activities have not revealed verified information about such a role.
Public statements by officials have not substantiated claims of Epstein’s cooperation with the FBI as an informant during 2003-2009.
What the Evidence Shows
The claim that Jeffrey Epstein was confirmed as an FBI asset and informant during the years 2003 to 2009 lacks substantiation in reliable public sources. Extensive investigations and reporting on Epstein's criminal activities, legal cases, and death have not produced verified documentation or official statements from the FBI or other government agencies confirming such a relationship.
Publicly available information, including detailed Wikipedia entries on Epstein's client list, death, and biography, do not mention any confirmed FBI asset or informant status for Epstein during the specified period.
Statements from officials and investigative reports focus on Epstein's criminal conduct, his connections to powerful individuals, and controversies surrounding his death but do not verify claims of him acting as an informant.
Assertions about Epstein's potential cooperation with law enforcement remain speculative or anecdotal without official confirmation.
Given the absence of credible evidence or official acknowledgment, this claim remains unverified and should be treated cautiously.