Isaiah L. Kenen, the founder of AIPAC (and AZC), was registered as a foreign agent of Israel under the Foreign Agent Registration Act (FARA).
Kenen was also the chief information officer for the Israeli Ministry of Foreign Affairs.
The American Zionist Council (AZC), the predecessor of AIPAC, was forced under Kennedy to registered as a foreign agent.
After Kennedy died, the issue dropped of the political radar and AZC reorganized itself as AIPAC.
AIPAC has managed to evade being registered as a foreign agent ever since.